Build "CJ3BL" 53 Willys

"CJ3BL"
This thread covers the build of my 53CJ3B. The "L" in the CJ3BL name stands for “Long", reflecting it’s lengthened wheelbase- plus my initials are “BL”.

I had a build thread on the old site. With its demise, I moved to Irate but was hesitant to start over on the build thread. I finally decided that creating a new build thread that includes all the work from the beginning, as well as finishing it here on Irate, was the way to go. So here's the first installment.

I've been tinkering around on this 53 CJ3B for most of my life. Here's a shot of my rig and me 63 years ago in 1962...I'm on the right.



My grandpa bought it new in 53, and my Dad inherited it and moved it to our house a little before this pic was taken. The engine eventually seized, and then it sat for a long time. My Dad and I rebuilt it when I was in high school. Later, in the late 70's /early 80's I swapped in a Pontiac Iron Duke 4, swapped to saginaw steering, 11" brakes, white spoke wheels and 31" **** Cepeks. During that period it also got run into by another car, bending the frame and crunching some of the body. Two frame shops plus my own efforts to fix what they missed got it closer to straight, but the frame was never quite right - it was bowed down in the center on the passenger side so it very noticeably didn’t sit level side to side. Later on, I started on a next build phase to install a 4.3 Chevy and some other mods, but the frame problem bugged me, and I stopped to correct it, but then got stuck. Moves, job demands, raising my kids, and my side career in a blues band led me to set it aside and it sat again for many years. As time passed, I then found web forums and saw cool rigs with home built frames, so I decided to take the plunge and start over by building a new frame, and put together an updated overall plan. The new plan also involved developing new fab skills along the way. I have been working on it for quite a while now, and have learned a ton from other builds and from forum member comments . Thanks to all the forum folks who provided feedback and advice along the way - many of which are here on Irate!

CJ3BL plan:
The concept is a somewhat traditional style leaf sprung CJ for street and trail, with most everything stepped up to be more stout and functional than the stock 53.

• Frame: 2"x5"x0.120" stack construction, with 2"x5"x0.188" bumpers. 142" long bumper to bumper.
• 96" wheelbase (16" longer than CJ3B, 2.6 longer than YJ/CJ7.
• 2.5" BDS YJ Springs, SUA
• Fox Shocks
• Modified Currie (now Rock Jock) Anti-Rocks
• Chevy 4.3 V-6
• T-18, Dana 18, Warn OD set high in frame for flat bottom
• Dana 44 Rear: CJ “wide track” width with GM D44 housing center, 2.75” tubes, full float RCV axles, with Chevy small spindle/Ford Hub/Chevy disc brake calipers/Ford rotors
• Dana 44 Front: CJ wide track width, GM D44 center section, with with Chevy small spindle/Ford Hub/Chevy Disc Brake/Ford Rotors, ARB Locker.
• ARB lockers front and rear
• 35” BFG's on older Weld forged wheels
• Warn 8274
• Original/modified grill, hood, mild high-line fenders, cowl. Back tub will be fabricated.
• Cage integrated with frame rails and rock sliders
• Body tub panels will mount to the frame/cage structure while keeping the overall look fairly traditional.

I don't have a CAD program, but I have an ancient version of Adobe Illustrator, so I laid out the design with Illustrator 2D line drawings. The layout is at 1:1 scale and has separate layers for each major design element so that I can turn on and off portions of the drawings as needed. I then shrink it to print 8.5" x 11" sheets to work from. It’s a long way from 3D CAD, but it’s worked well in helping to avoid major packaging oops so far.


I've been working on this iteration for a few years, learning new skills as I go. This thread will show the build in the order it occurred. It will take some time to post the earlier parts of the build, as I’ve taken a lot of pics of steps along the way. Once the old stuff is posted, I’ll start posting real time updates. Before heading into the way-back machine for old build steps, here’s a few pics of where the build is currently at:




more in the next post...

Here's a few more pics of the current state of the build:

Now I'll time travel back to the beginning of the build. I took a lot of step by step pics along the way, so it will take some time to post all of it...

Front Bumper

I started the build with the bumpers and then the frame rails. Both bumpers are 2" x 5" x 0.188". The frame rails are 2" x 5" x 0.120", with the width set at the stock 27.5” centers. All welds are TIG, using a Lincoln Square Wave TIG 175.

Before bumper build stuff, here's some thoughts on the choice of 5" rails, since 2" x 4" rails are more typical on stack tube frames. I went with the 5" height rails for the following reasons:

The 5" center rail provides a "kick" height to the bottom of the front and rear rails for better axle/steering clearance at full stuff- it's about the same as the original frame elevation over the axles ( the original stamped frame rail underside arch elevation was 5.5”, ie the peak height of the underside of the arch vs the lower flat center section of the rail). The larger 2” x 5”section also increases the 2" x 5" x 0.120" stiffness to about the same as 2 x 4 x 0.188" but with less weight. The build is somewhat buggy style with no body mounts separating the body tub floor from the rail. The roll cage will attach to the frame directly, and having decided that, to me it didn't make sense to have flexible body mounts with a body assembly and cage that then move relative to each other to fatigue the body metal. Since there will be no body mounts, it gets rid of the original 1" of body mount pad plus underfloor hat bracing above the rails. The new floor bracing will be flush with the top of the rails. So the 5” rail height from the rail bottom to floor surface will be essentially the same as the stock 4” rail with 1" body mounts + hat channels, but with stiffer 1" taller rails. I also think that the proportions of the bumpers and rails fit well with the tall grill/tall hood 3B appearance.

Up front with the 5” tall rails, the elevated brackets that the grill would normally mount to would be an issue as they would cause the grill to sit too high relative to the tub. Instead, the grill will mount directly on top of the rail with no elevated bracket. The rails will have a threaded boss internal to the rail, and the grill will bolt to the rail with a thin rubber washer cushion, and with bolts that have a nylock feature along the threads to keep them from loosening. My original frame had the elevation height of the grill mounting bracket top at 9.8" from the lower edge of the central rail. Mounting the grill directly to the top of the 5" stacked rail places the grill at 10" elevation - the same relative height as the original , so it will align with the tub (and have no increase in center of gravity from the frame layout). One concern with directly mounting the grill to the top of the rail is frame flex fatiguing the grill, but the tall rails a 2" x 5" cross member that will sit right behind the grill (with a through hole for the steering shaft) will make the frame pretty stiff and stable. In addition, I plan to extend the cage structure into the engine compartment - so that will further reduce front frame flex.

On to the front bumper builds. Since I laid out my design measuring and mocking parts up first, I decided to put D-Ring mounts, winch mount, pintle hook, and fuel tank mounting together before the bumpers are attached to the rails, as it's much easier to work on them on the bench.

I found step by step photos on other builds to be really helpful, so I’ve tried to do the same with plenty of photos. Here's the finished Front Bumper. It's 50" wide. I'm trying to keep the overall vibe in a "beefed up traditional" direction.





Here's step by step build info. The pics follow this sequence:
- Taper cut bottom ends, and filed chamfers for good weld penetration.

-Then layed-out and drilled starter holes for cutting holes for through-bumper D-Ring mounts from TMR:

- Cut the D -ring holes front and back using a portable jig saw, with the blade shortened by cutting it off with a grinder. This keeps the blade from banging into the opposing inside wall of the bumper tube.

- Filed for fit, while checking with a combo square to assure the mount will be perpendicular to the face of the bumper.

- Welded D Ring Mounts front and back.

- The 8274 winch is mounted so the fairlead is under the bumper to keep weight low and provide better airflow to radiator ( similar to Meiser’s Rango build on the old site). I also used Meiser's countersunk socket head screw idea on the upper two mounts. I have an old Delta wood lathe from the 40's that has a speed reduction pulley set and cross slide to allow simple metal turning, so I used it to make countersunk winch mount bosses, with outer end chamfered for good weld penetration.

- Cut out winch plate from 0.250" 1018 cold rolled plate with hand held jig saw.

- Made some side gussets to support the lower part of the plate. The gusset corners have an ample radius to provide smooth edges at the sides adjacent to the fairlead. The winch plate, mounting boss, and gusset welds were then made. I fixtured the plate with some short lengths of square tube clamped to the back to keep the fairlead flange from warping inward while stitch welding to bumper. I decided to stitch weld rather than welding the full perimeter of the plate to reduce heat and bumper warp. The unwelded edges will be sealed with body sealer before paint to minimize rust.



More in next post...

Here's the rest of the front bumper fab:

- Ground and filed the winch boss welds to make them pretty (the welds don't see much load) The black tape on the sides is Gaffer's tape. I put it around the weld to keep from scratching up the surrounding area while final filing the weld flat. It comes off when done without a gooey mess.

- Fabbed bottom taper and end caps cut from the same tubing as the bumper to preserve the edge radius for a clean look.

- Tacked bottom taper cap, then fit and tacked the end caps

- Finish welded taper and end caps

- Finished bumper front

-Finished bumper back



Next up, the rear bumper.

I like the rolled tube on the rear wheel wells!

Good eye dnsfailure! They are kind of a “roll your own” approach. I thought about having some tubes rolled by a commercial outfit, but figured it would be spendy for only 2. I have a Swag roller but they don’t have a 3” wide die, and I had some doubt on whether it could roll 2x3 tube with the shape retained well. Instead I used it to roll pieces, then weld them together. It was a lot of work, but I’m happy with the result. I’ll have pics on the wheel arch fab posted pretty soon.

Rear Bumper Part 1

The Rear Bumper is also 2" x 5" x 0.188". I plan to delete the original style body panel that's below the tailgate, so the rear frame rail will not have a "kick down". The rear frame rail will extend straight back and the bumper will be level with the frame rail. The top of the bumper will form the lower opening for the tailgate. The fuel tank will be positioned in the typical later CJ location, but mounted higher. The rear floor will have a short rise above the tank and that panel will be removable for access. The rear wheel body opening will not be comp cut. The rock sliders will follow the arch of the wheel well and terminate into the rear bumper corners. More on the bumper corners in the next post.

I also plan to run a pintle hook to tow a military style trailer for camping that I hope to build when the 3BL is done. The pintle is positioned so the top edge of the pintle latch is just below the level of the opened tailgate.


Here's pics of the bumper build in the order that it went together:

- The first pic shows the pintle hook mounting bosses, internal reinforcement plate, and the TMR D-Ring mounts. The pintle reinforcement plate slides inside the tube from the end, has one rosette weld to position it, and then the Pintle mounting bosses bear against it. I turned the Pintle bosses from 1.25" 1018 cold rolled bar. The large diameter bar stock bosses provide a large clamping surface against the interior reinforcement plate. The bosses are countersunk to accept 1/2" cap screws inserted from the back, so there is nothing protruding on the inside face of the bumper. This allows the fuel tank to be mounted close to the inside face of the bumper to maximize clearance with the rear differential at full stuff. The D-Ring mounts are spaced 27.5" apart, so the backs of those protrude inside the frame rails, as on the front bumper.

- The fuel tank mounts to the bottom of the bumper at three points using 1/2" NF Screws. I turned and threaded some bosses that are welded with two rosette welds at each side to mount inside frame. Shown in the picture is a boss and a little fixture I made to clamp the boss in place for welding.

- The third pic shows a fuel tank mounting boss ready for welding. (I used the scribe to dig in to the surface of the boss to keep it from spinning as I tightened the fixture screw).

- Fuel tank mounting boss rosette welds

- Pintle reinforcement plate slid inside rail from open end, then bolted in place for rosette weld to fix it in position

- The pintle mounting bosses were then bolted in place in the back of the bumper to clamp them for welding. Edges were chamfered for good weld penetration.

- Pintle bosses finish welded.

- TMR D-Ring mounts were then welded front and back

- Pic of overall bumper with Pintle mounted temporarily

CJ3BL said:

Good eye dnsfailure! They are kind of a “roll your own” approach. I thought about having some tubes rolled by a commercial outfit, but figured it would be spendy for only 2. I have a Swag roller but they don’t have a 3” wide die, and I had some doubt on whether it could roll 2x3 tube with the shape retained well. Instead I used it to roll pieces, then weld them together. It was a lot of work, but I’m happy with the result. I’ll have pics on the wheel arch fab posted pretty soon.

Click to expand...

I've got the harbor freight roller with the swag stuff welded to it, I've never rolled 3" wide, but I do 1x2" .120 fairly easilly in either direction. So you rolled flat bar, and welded them up? Nice! How well did the flat bar roll on edge? I have one of those dies, but I've not yet needed to roll it on edge yet.

Rear Bumper Continued

Here's some context for the outer corners of the rear bumper. I plan 2" x 3" x 0.120" rock rails that will run along the body side, including a short section behind the rear wheel that transitions into the rear bumper. The body floor pan will attach directly to the top of the frame rails and rock rails. The roll cage will weld to the rear bumper/rock rail structure. The body side panels will also attach to the top of the rear bumper and side rock rails, with the rock rail protruding 5/8" outward beyond the body side panel. At the rear of the body, I want the bumper face to be flush with the body like the original jeep, but have the bumper ends curve at the corners to smoothly transition into the side rock rails.

This post shows the forming of the rounded rear corners of the rock rails that will attach to the ends of the rear bumper. I've left them long-for leverage while forming the corner radius, and I'll trim to the rear wheel well area once the rear axle is positioned.

Here's the steps in the order of the pics

-Cutting the 2" x 3" rock rail tube in preparation to forming the corner curve. The curved cut is the same top and bottom and serves as a guide for the curve forming. Each side of the tube was cut separately using a hand held jig saw set to 90 degrees ie straight up and down. The blade is shortened by grinding off about a half inch to keep it from hitting the opposing side of the tube. I use a wax stick to lubricate the blade so it lasts better. The cut edge is cleaned up to the scribed layout line with a file (or a grinder first if there's much excess material). I then rough cut the chamfer with a 4" angle grinder, then clean it up with a file.

- For the the long straight chamfers I use a Vixen File. It cuts fast and also levels the surface nicely. It also has no teeth on the side edges, so it's nice for corners - you can file each side of the corner separately. It also leaves the surface free of grinding grit so you get a good weld. The pic here shows the Vixen file being used on the front bumper end welds, which it also works well for.

- A Swag finger brake was used to start the bend with light pressure, stepping a little at a time along the area where the curve starts. I couldn’t form the full curve with this approach as the finger collides with the tube edge, but starting the bend this way reduced the "cave in" of the outer face of the curve due to the edge radius of the tube section being stiffer than the flat 2" side.

- I made a little bending mandrel that's just a section of round tube welded to some plate sides with a square tube handle welded to it to mount it in my vice. The curved surface goes inside the tube as a mandrel for the curved bend. This pic shows it being set up.

- This pic shows the curve being formed using the mandrel tool. The mandrel again helps to keep the outer face of the curved tube wall from caving in

- The formed curve springs back a bit. The pic shows how it was clamped for tack welding

- I then finish welded only the bottom side of the curved joint. The top side will be trimmed to fit the top of the bumper.







The next post shows attachment of the corner pieces to the main bumper.

dnsfailure said:

I've got the harbor freight roller with the swag stuff welded to it, I've never rolled 3" wide, but I do 1x2" .120 fairly easilly in either direction. So you rolled flat bar, and welded them up? Nice! How well did the flat bar roll on edge? I have one of those dies, but I've not yet needed to roll it on edge yet.

Click to expand...

Good to know! While the rock sliders are 2"x 3" tube, the wheel aches are 1.5" x 3". I chose the 1.5" tall section height to match the look of the stock front fenders which are about 1.5" tall on their outer edges. The top piece of the fabbed wheel arch tube is cut from rectangular tube, preserving the corner radius of the tube. That ties them in visually with the tube radius of the rock rails they join with. They were then rolled the easy direction, with the roller chosen to not mash the corner radiused edges. The lower 3" wide part of the tube is just 3" flat stock , rolled the easy direction. I chose flat as it is easier to fit at the join with the rocksliders. You nailed it on the sides - they're 1" flat bar rolled on edge, the hard direction. The Swag hard direction rollers worked remarkably well. I just needed to be careful in guiding the piece so it didn't develop a "lean" as it formed. I was surprised at how well rolling the hard direction worked!

PS: It took me a while to recognize your '46 in your avatar pic. You did a great job on that build! I also remembered that you use your roller for other decorative metal work. I appreciate your past comments on the old build thread. How's everything going?

Rear Bumper Wrap Up

With the curved rock slider / bumper ends parts completed, I trimmed the bumper and the bumper rock slider ends to configure their weld joint. The pics show the following:


- Set-up the parts on my old table saw, aka welding table. The pieces are clamped upside down for initial tacks as this keeps the top surfaces of the bumper and the bumper ends/rock rail to be held co-planar against the table top.

- Fit caps for the lower taper of the bumper. These are cut from the same 2" x 5" x 0.188" tubing as the bumper.

- After tacking the bottom side, the parts were flipped over and clamped using a section of tube under the side rock rail ends to keep them coplanar with the top of the main bumper tube. Then the top joint was tacked. This shot also gives a good sense of the overall bumper/rock rail corner configuration.

- Proceeded with finish welding. The pic shows a view of the the bottom of the bumper with the inside corner welds complete and the tacked lower cap about to be finish welded.

- The last shot is the top side of the curved rock rail / bumper end weld to the bumper. It shows how the top side joint fit up was done- which is different than the bottom joint. On the bottom side , the outer formed curve piece of the rock slider / bumper end was welded to the cut curve of the rock slider prior to bumper assembly. On the top side, the outer part of the bumper tube was cut to fit the curved part of rock slider, and the rock slider top face was cut back to make a butt fit to the inside edge of the bumper tube.





With the rear bumper done, it's on to making the frame rails...

Frame Rails

Time to make the frame rails! The rails are stacked 2" x 5" x 0.120" A500, Grade B. I wanted to do something a little different for capping the rail angle cuts at the stack joints. The idea is to form a continuous curved cap, and also include an integral reinforcement tab at the stack joint. I'll show pictures of the end cap fab and then describe my reasoning for doing it this way, as it's easier to describe with the pics.

- I wanted to have all the stack rail end caps ends have a consistent profile, so I made a template for layout. It has two 0.120" plates. These were tacked together at the corners, then the template profile was laid out, scribed, and cut with a jig saw. The profile was cleaned up with a file, then the tack welds were separated, leaving two plates with matching profiles and reference edges:

- Two sections of 2" wide rectangular tube were cut to bridge the template halves together. The bridge piece height was set so that the template halves are positioned at the desired height when clamped on the frame rail tube. The bridge pieces are welded at the bottom edges of the side plates so the the sides remain flexible enough to wrap around the rail tubing. The second photo shows finished template.

- The next pic shows the template clamped to a rail for scribing the layout of angle cuts, end cap, and reinforcement tab

- After scribing the layout, the rail tube was cut with a jig saw, and the edges cleaned up and chamfered. The reinforcement tab at bottom left has the 0.120" thick tube wall thickness, while the end cap on the right is 0.250" high- which retains the original tube corner radius.

- Here's a detail shot of the corners of the cut. I drilled a small hole first, then made the jig saw cut. The hole and edges leading to it were chamfered with a tapered burr, while the rest of the chamfer was made with a grinder and file. The corner hole was made to avoid creating a stress riser at the termination of the jig saw cut, and to achieve full weld penetration.

- The rail end cap was formed by hand using the same forming mandrel I made for the for use on the rear bumper ends, shown previously.

- The next pic shows the mandrel clamped in position for making the bend. I had tried it out on a prototype scrap section of rail material and marked the placement depth with a felt pen on the handle of the mandrel, in order to have a consistent forming and fit on all of the rails. The marked line is aligned with the end of the cap section then clamp in place for bending.

- After clamping the mandrel to the rail cap, I then clamped the rail to my table saw top with the mandrel hanging off the end of the table, put a short rod in the mandrel handle to get more leverage, and hand bent the cap. The cap forms around the 2.5" radius curve cut in the side of the rails, while the mandrel helps keep the face of the bend smooth and flat. The bend can't make it all the way due to the mandrel handle getting in the way, and the cap edge needs final fitting against the reinforcement tab. To test and adjust the fit, to complete the bend, and to tack it in place I clamped the rail to my "workstation" (which is an old Delta Wood Lathe bed). The pic shows the clamping arrangement. Once the fitting was done, then the formed cap was tacked to the rail.

- The next pic shows the completed tacks. You can see how the end cap is fitted to the reinforcement tab- the corners wrap around the tab to make for a nice fit for welding.

- Final welds were done in sections about 1.5" long, alternating sides to minimize warpage. The last pic shows finished cap welds. The reinforcement tab will be trimmed into a curve when the rails are fitted for stack welding. All of the top and bottom stack rail sections have this cap and tab shape.






Doing 8 of these ends on the rail sections is a grunt versus welding a flat cap on the end of a flat angle cut, so why bother?

I thought this approach was worthwhile for a few reasons:

-I like welding the caps of the rail sections before welding the stack joint. The walls of the tubing tend to flare out at the angle cut from relief of internal stress in the tube when cut. I think welding the cap in place before the stack weld makes the tube more stable so that stack weld shrinkage is less likely to move the rail alignment around. This can also be done with a flat plate cap, but welding the cap first opens the door to the rest of the approach…

-I like the aesthetics of rounded corners. It was fun to figure out a way to make them.

- The rail stack welds have a higher stress area where the rail angle cut ends on the adjoining tube. I think that the reinforcement tab formed from the tube wall in the above approach provides additional material overlap and a more distributed weld transition at the junction of the stacked tubes. I think this reduces the stress riser at the ends of the stack vs. a flat end cap with its weld running straight across the rail of the adjacent tube right at the higher stress transition point.

Looking ahead to how these will go together, the end cut angle I chose is 45 degrees. The stack weld overlap of the rails at the stack joint is going to be 12" from "tab tip" to "tab tip". The reinforcement tabs are 1.5" long on each rail section so the full tube rail-to rail overlap will be 9”, which I’m thinking is sufficiently long.

I chose that design for a few reasons. First, I was trying to strike a balance between having a long stack weld joint for strength, versus shrinkage from long welds causing the front and rear frame tubes to tip downward - potentially not by the same amount on each rail. I often struggle with managing weld shrinkage to keep things aligned as well as I would like. After finishing the the stack joints, the ends did end up well aligned - see later posts.

I’m using an anti-rock torsion bar at the rear, and the bar will be positioned on the front of the angled taper of the rear rail. The 45 degree tube end taper angle worked out well in the layout for positioning of the torsion bar mounting tube on the front of the rail taper, positioned just behind the floor rise.

The front rail cap angle matches the rear, and it’s positioned in the layout well ahead of the firewall floorboard angle so there's more room for steering and hydraulic clutch line routing. Having shallower angle rail end caps at the front stack joint would look more like the original rail shape, but I didn’t like the idea of much longer stack joint welds as mentioned.

Before making the stack welds to create the full length rails, and attaching the bumpers, I made some fixed spring hangers and added mounting bosses for those and other frame attachments to the frame rail sections while it’s still easy to place stuff inside the rails...

Fixed Spring Hangers

Here's the fixed Spring Hangers I made. I initially used RE 2.5" lift YJ springs, but later changed to BDS 2” lift YJ springs, (more on that tuning decision later in the thread). I want to have the fixed hangers set the spring close to the rail. The first ones I made were 2.5” from the rail to the spring eye hole center. I later tightened this to 2.375” when I changed to BDS springs. The design also tapers so they don't snag as much as straight sided hangers would. They bolt on to the rail, and will also have a small weld at the ends to minimize “fretting” from vibration. I like the idea of the hanger being easy to replace.

Here’s pics showing how the first ones came together:

- Blank cut from 0.188" 1018. Bend lines marked with felt pen.

- Formed the part with a SWAG finger brake. The bends need to be made a little bit at a time alternating between the angled and parallel bends.

- I made a thinner finger clamp plate in order to gain more part clearance on the last part of the bend - as shown in the second finger brake pic

- Completed bends

- Sides welded and holes drilled

Internal Frame Details

I plan to bolt on the fixed hangers made in the last post. I’ll also add some small welds at each end to prevent fretting of the joint from vibration. I won’t make the welds until I have the suspension well dialed in, as the bolt on approach also allows for some fine tuning by revising the hangers if needed (I took advantage of this of later when changing to BDS springs, and made some new hangers with the dimensions tweaked).

The shackle hangers I'm using are Slickrock investment cast steel parts made for the back of late CJ's. I plan to bolt them on too, as on a late CJ, also with some small stitch welds at the ends. I like the low profile and strong design of the Slickrock hangers. Currie (now Rock Jock) and JKS used to sell them, but it appears they are no longer in production. Bummer, because they are really a nice part.

On the top of the front frame rails I also want threaded mounting holes for recovery hooks, a front anti rock torsion bar, and grill mounts. I'm using 1/2" NF grade 8 cap screws for all of these, except for the grill mounts (which are 3/8" NC nylock thread locking screws as mentioned earlier). I made a pile of tapped bosses from 1" round 1020 cold rolled bar stock, using my old Delta wood/metal lathe. The grade 8 bolts have about 3x the tensile strength of the bar stock, so I made the threaded length of the bosses > 3x the bolt diameter and will use cap screws that engage this length to try to get close to a comparable match in strength, although the tapped threads aren’t as strong as commercial rolled threads would be. Hopefully they’ll work out OK. The bosses retain the 1" diameter face at the plate, but then taper to reduce weight. They are welded to 0.125" 1018 reinforcement plates, and then the plates are welded in the rails with a few rosette welds. This will be a stronger, although heavier, than welding threaded bosses directly into holes in the rails.


Here's pics showing the plates and threaded bosses.

- The first pic shows the different reinforcement plates and bosses. The plates on the left are for top of rail tow hook, torsion bar, and grill mounts. Middle plates are for fixed spring hangers, right plates are for shackle hangers. The bosses are the same config for all but the grill, are on the far right. The grill bosses fit smaller, stock size grill fasteners

- The second pic shows a welded shackle hanger boss plate

- Next is a welded fixed spring hanger plate

- Welded tow hook/antirock/grill boss plate with tow hook attached

- All of the boss threads were chased after welding, using a drill press to guide the tap

- All ready to install

- Installation of the boss plates: Used a box end wrench on a boss to hold the plate inside the rail, then clamped in the rail using cap screws into the bosses

- Then made rosette welds to lock in the boss plates

- Rails with reinforcement plates and threaded bosses installed. Left to right are the bottom side of the center rails, the top side of the front rails, and bottom side of the rear rails.





Next up, the steering box mount.

Saginaw Steering Mount

I also made the steering mounts and prepped the front rail for them at this point. I'm using a "76" casting saginaw power box with 4 mounting ears. I decided on the position based on mock up work that I did when doing my layout drawings. This post shows the mounts and rail prep. I'll weld the mounts in after the rails are stack welded, as the mounts would be in the way of fixturing the stack welds if I put them in now.

Here's a step by step through the pics:

-Scribed the hole layout on the rail for the upper two mounts based on my lay-out drawing.

-Rough cut the holes with a hole saw, then a rotary burr.

- Final fit using the scribe marks and the mount insert as guides to achieve a close fit.

- Next pic shows the upper two mounting bosses, and the 0.188" 1018 reinforcement plate that will fit inside the rail. The boss is turned from 1.25" CR 1018 round stock. The 1" turned end mates with the box. The "ledge" transition from 1" to 1.25" bears against the reinforcement plate inside the rail. The large end is chamfered for weld penetration of the weld at the outer rail. The mount is countersunk for use of allen head cap screws- so that the front tire doesn't hit protruding bolt heads. I used the large 1.25" stock so that I could create the inside ledge, which traps the boss in the rail. If all welds failed the box can't move inward. The ledge and reinforcement plate mechanically prevent the mount from pulling through the rail towards the inside. The ledge transition on the bosses and the mating corner of the reinforcement plate both have a small radius to avoid a stress riser at the joint.

- The next pic shows the steering box side of the mounts.

- The weld chamfering and countersink of the mounting boss is shown at the outer side of the rail. The rail will be chamfered as well before welding.

-The lower steering box mounts are also turned from the same stock, but the transition from the 1.25" to 1" section occurs at the inside face of the frame rail. The larger 1.25" diameter bar stock provides a wide, flat contact patch where they meet the rail. I'll add a tube section between the lower mounts for reinforcement once it's time to weld them on.

- The end view of the inside of the driver side front rail shows the upper steering box mount, steering reinforcement plate, recovery hook boss plate ,and shackle mount boss plate assemblies.

- I used my trusty vixen file to knock down the inside rail tube seam so the steering reinforcement plate sits flat. Then welded the plate in position with a few rosette welds.

-

Rear Cross-member

Made some cross members before putting the pieces all together into something that looks like a frame! The front cross member behind the grill is just a section 2x5 tube- nothing interesting.

The rear cross member has three mounts in it for the fuel tank, similar to the rear bumper. I wanted to make sure the differential clears it at full stuff, so I made it from 2" x 3"x 0.120" tube, with the 2" in the vertical direction. It sits flush with the top of the rails. On the bottom I want it to transition to a taller footprint against the rail tubing for greater strength and rigidity.

Here's what I came up with, as shown in the pics:

- Cut along the edge of the 2x3 tube to separate one of the 3" wide faces on each end, preserving the tube corner radius on the separated section. then bent it outward. To do this I used my shop press as a clamp- to hold an old lathe chuck against the part, and then bent it down by hand with a 2"wide piece of aluminum clamped in it for more leverage.

- Next pic shows the resulting formed ends

- Traced and cut out a hard cardboard template for filler plates. Used the template to cut 4 filler pieces from 0.120" 1018, and tacked them in place to close the formed end opening

- Welded filler plates

- Drilled fuel tank mounting boss holes and made chamfered holes for rosette welds. The fuel tank mounting holes in the rear bumper and this cross member are far apart, so I didn’t want to use the reinforcement plate idea that I used for shackle hangers as the plate would be very long. These bosses are made from 1.25” diameter round stock so the base of the boss has a wide footprint to distribute the clamping force more widely on the rail, whereas the ones mounted with reinforcement pates have a 1” base diameter. Both types of threaded frame bosses taper to cut down on weight. The 1.25” bosses are wide enough that I could put a rosette weld on each side to fix them in place in the rail without screwing up the bolt hole between the welds. The pic shows a cross member fuel tank mounting boss and rosette weld hole pattern.

- The next pic shows the handy fixture to hold the boss in place for rosette welds:

- Trimmed ends to bring the cross-member width to 25.5". Here it is in place , viewed from the underside. I got the taper to end just where I wanted it- right at the frame rail radius. Got lucky!

- Finished rear cross member

Frame Assembly

Time to put all the pieces together! Here's the step by step descriptions in the order of the pics:

- The bumper ends of the frame rails were cut to length and detailed to get a tight fit with the bumper tubes, with a small lip to fit tight against the bumper tube radius

-The rail reinforcement tabs at the stack joint ends of the rails were marked with a template, then trimmed. The tip of the tab has a small flat spot remaining untouched - to preserve it as a measurement point for positioning the rail sections to each other. The rail stack overlap needs to be accurately positioned since the spring mounting position on each rail section are already set - i.e. the rail overlap has to be accurate to have the eye-to-eye spring mounting distance end up per plan.

- Placed cap screws in the fixed spring mount bosses on the central rails as alignment points, then clamped the rails together with the fixed spring mount holes aligned.

- Did the same to align the shackle mount bosses on the front and rear rails

- The rails to be joined were then clamped together to my table saw top and "lathe bed workstation". I made a base for the table saw to sit on that has adjustable feet. The "workstation" legs that I made that also have adjustable feet, and I made the legs so the lathe bed surface sits nominally 5" higher than the table saw top, which is the stack height of the frame rails. I adjusted the heights and level in all directions until happy that everything was lined up as best I could make it. Lots of crawling around on the floor tweaking the adjustable feet. The machinists level in the pic foreground was my grandpa's. It's super sensitive, which can drive you nuts, but it's really helpful. The bubble moves about one graduation mark with only an eighth of a turn of the leveling feet.

- There's a bunch of clamps at the stack joint and beyond. The 2" x 4" tubes running lengthwise are to keep the rails straight laterally. The 2" x 4" scrap tube running cross-wise has an aluminum block under it that fit nicely to clamp the tabs to the adjacent rail, while leaving the tab tip exposed for a big tack weld to set the rail stack overlap distance. Before setting the clamps I used combo squares and a ruler to check and set the top tab to underside tab tip-to-tip spacing at the reference points on the tab tips. The distance is 12" tip-to-tip. This results in a 9" overlapping length for stack joint of the rails excluding the tabs.

- The first tab tacks were made with the rails upside down so that I could measure and align the spring mounting bosses easily (as they faced up). the pic shows these first tab tacks

- After making the first tab tacks, the rails were partially unclamped, flipped over, re-clamped, double checked for alignment, and then the top tabs were tacked. The rails were then rotated 90 degrees to lay flat to tack the stack weld area. One of the 2x4 clamp tubes along the length the rails remained in place with the underside of the rail clamped directly to the table saw surface. I used a saw horse style stand set level with the table saw top in place of the lathe bed workstation to support the length of the rails. Once fixtured in this flat position, tack welds were made on the sides of the stack weld joints as shown


More frame assembly in next post...

Frame Assembly Continued

- With stack joints fully tacked, I welded the reinforcement tabs

- Then the rails were set on their sides again and clamped for stack final welds: The 2x4 tubes clamped on top are to maintain lateral straightness of the rails.

- The stack welds were made a short section at a time, flipping the rails over together to alternate sides in completing each section. The numbers scribbled on the rails show the sequence. I made welds at the ends first, as I thought locking these in first might help control shrinkage. Not sure if it made a difference, but it turned out well in the end, so maybe it helped.

- With the stack welds complete I leveled high spots of the welds with a grinder and file - only in the areas that will be under side plates so the plates fit tight to the rail. Then the rails were clamped for side plate welding (photo shot after first set of plates welded)

- The side plates were tacked at their corners, then welded in an alternating sequence, letting the parts fully cool after each section completed. The sequence is shown marked with felt pen. I don't know if the sequence was ideal, but it seemed to make sense as far as alternating the direction of shrinkage and potential misalignment effects, and it turned out well with good alignment.

- Complete frame rails!

- Finish welds of rail stack joints with side plates

- As far as weld shrinkage/warping, I'm happy with the elevation rail alignment to each other as well as the side to side straightness. The last pic shows the elevation alignment at the ends , with the center of the rails clamped to my table saw top. Looks good. Phew!

- Steering box mount welds. With the frame rail sections welded together, the steering box mounts could be final welded. (they would have been in the way of clamping arrangements if done before rail assembly). To make it easy on myself, I tipped the frame on its side for easy access and a horizontal weld position. The mounting bosses were bolted to the steering box in their positions on the rails to assure good alignment to the box, and then small tacks were made. The box was then removed and the final welds made. This pic shows the welds at the inside of the rails. It also shows that the rosette welds locating the internal reinforcement plate were smoothed for clean aesthetics (they carry no load). The frame was then flipped over and the bosses were welded at the outer rail face. The frame was then flipped 90 degrees (ie upside down) to make the welds along the 2" rail width of the lower bosses.

- Finished steering box mounts. After making the boss welds, then a reinforcement cap was made from a section cut from 2" x 5" tube to bridge between the lower bosses. This was then welded at the rail and bosses.

Frame Assembly Continued…some more

Now to connect the rails, cross-members, and bumpers. The pics show more steps in assembling the frame in the following order:

-I had some 2x3 tube that had deep surface gouges that I didn't want to use on the rig build, so I used it to make some saw horse style stands. There's two tall stands and two short stands, with a 5" height difference, all with adjustable feet. The stands can have a top cross bar mounted like a saw horse, or bolt directly to the frame rails at the threaded frame bosses. Not as good as a frame table by any means, but I don't have the dough or space for that. These can be taken apart for storage and used for other stuff.

- The rails, bumpers, and cross members were set up using the stands, with the short stands bolted to the center rail fixed spring hanger bosses and the tall stands bolted to the shackle hanger bosses. There are two temporary cross-member style spacers in the center. They have a tab on the top that rests on the rail so they don't fall out. Two of the oposing center stands have a pipe clamp set up as a spreader (or clamp as needed) , to tweak the diagonal corner distance as needed to obtain square rail alignment. The end stands support both the rails and bumpers on the flat top surface of the stand. While the rails are bolted to the stands, the bumpers are clamped.

-Thie next shot shows additional rear bumper clamps for tacking. The lower clamp is pulling the bumper tight against the rail (the tapered black things the clamps are bearing on against the stands are slickrock shackle hangers tipped on end - I needed something tapered and sturdy to get the clamp positioned. and they were perfect!) The rear large clamps hold the bumper down against the top of the stand. The small orange Jorgensen clamps are holding two 1" diameter round stock pieces that are used as measurement points for measuring the front-to-back diagonals to assure the frame set up is square. I used the round stock as a reference point because it can be used both before and there are weld beads made at the inside corners.

- Spent a lot of time crawling on the floor adjusting the stand feet to level everything in all directions as well as checking and adjusting for square

- Once everything was positioned, level, and clamped, then the bumpers and cross members were tacked on top and near the bottom corners. Then changed the clamp set up for finish welds. For the bumpers, weld heat solely on the inside of the bumper tends to make the bumper ends curve inward from shrinkage of the tube wall. I wanted to keep the bumpers as straight as I could, so after tacking the clamping was changed to create some pre-load for the finish welding. The preload pulls the bumper in the direction opposite the anticipated weld shrink caused bowing on the bumper. The first of these preload clamping pics shows the front bumper pre-load clamping.

- The next pic shows the rear bumper pre-load clamps. The rear bumper clamping set up also has a pipe clamp spreader to preload the rock slider ends of the bumper - again to oppose the tendency to pull inward if the bumper bows from final weld shrinkage.

- The bumper top joints were then welded first, both bumpers, checking the frame diagonal lengths and levels before each weld, and letting each weld cool before checking and welding the next. Then I did the side beads for the bumper to rail the same way- check, weld, cool, then check level and diagonals again before the next weld. The pic shows a back bumper weld.

- Then moved on to weld the cross members, with the same check, weld, cool, check approach. When these were done on top and sides, then everything was unclamped and the frame flipped over using an engine hoist and then reclamped, remeasured, and finish welds of the underside joints completed. The pic shows the underside of the welded rear cross member.

- Shackle hangers and fixed spring hangers were then bolted on and the planned eye to eye spacing of the hangers was confirmed.

- The last pic shows the completed basic frame assembly. Progress!





Overall it turned out pretty well. The difference in diagonal corner measurements is less than 1/16" - it's very square. The bumpers and cross members are also level using the sensitive machinists bubble level. A lot better than my bent old frame.

Despite the pre-load clamps, the bumpers still ended up with a little shrinkage caused curve but this is much better than other similar joints I've done in the past without any pre-load clamping for shrink control. Overall, I think the pre-load worked well).

The only significant concern area is that the temporary spacer cross members were tight between the center rails, indicating that the front and rear cross-member welding resulted in some shrinkage of the inside rail surface - causing the center to bow inward. I pulled the spacers out to measure how much inward bow there is. It's about 1/4' total, 1/8" per side. It would likely have been worse without the spacers in place during welding, but a concern none the less. I plan to weld a 2" DOM tube cross-member/antirock torsion bar mounting tube at the front of the rear rail taper, plus a cross member under the engine for engine mounts and oil pan skid plate if I can fit it. There will also be outriggers added for the rock rails, plus floor supports. All of these elements provide an opportunity to further constrain the center rails to the desired position, so I think it will work out OK if I pay attention.

If I was to do it again, I think making the permanent cross members and the temporary cross member spacers just a little a little wider than the intended frame spacing could compensate for weld shrinkage at the permanent cross member to rail welds - to preload those joints so that when the temporary spacers are removed the center section would pull in to the target width. This method could be confirmed with some test parts. I'll try that next time...

Grill + Lower Radiator Mounts

The overall drive train and body layout I put together references a lot of measurements to the face of the grill, so I decided to mount the grill as a next step. The wheelbase stretch to a planned 96” allows stuff to fit reasonably vs the original 81" wheelbase. The engine bay length between the grill face and firewall is planned to be stretched 3.75” vs. stock, although that could change a little once I get all the major assemblies mocked up in place and look at the fit.

The radiator is from Ron Davis , 24 W x 19” T x 3” D, "Two Row, Double Pass Off-Road". I plan to position it about 3" back from the grill shell. This is about 1.5" closer than the stock radiator shroud / radiator positioning. I don't want to push it all the way forward to the grill shell as I want to keep the original headlight buckets intact. The 3" spacing to the grill also works out nicely with the front cross member. The cross-member sits between the radiator and grill shell with the steering box shaft U-joint positioned so the joint axis is at the center of the cross member pass thru tunnel - which optimizes the joint clearance. The radiator core will be centered behind the grill slots, rather than offset like the original - so I removed the original shroud and will be fabbing a new one later on.

Here's a few pics:

-Removed the original grill shroud by grinding down the spot welds on the shroud flange, stopping short of going through to the grill panel. Then popped the weld open using a chisel wedged into the joint, keeping the chisel angle flush to the grill panel to avoid deforming it. The shroud flange breaks free without removing material from the grill panel.

- Since the original shroud was offset, the flange on the outer grill slot stamping was angled. I straightened the flange using some clamps and some metal scraps as bucks

- Shroud gone, straightened grill slot flange.





I'll be adding a new shroud with an internal chaff screen once the radiator is fully mounted. That will be much later, since the top radiator mounts will tie into the engine bay cage. But getting the lower mounts done now will help with engine positioning.

With the grill shell mounted to the rails, the lower radiator mounts on the front cross member were worked out. The vertical position of the mounts align the lower edge of the radiator core area even with the top of the cross member. This places the top of the rad open core area just above the grill slot tops - nicely centered to the grill opening.

Here's the step by step on the lower mounts:

-Cut a section from 2" x 5" x 0.120" tube for each one. The short direction of the tube section provides a gusset on the mount. I cut the shape out then formed two tabs that serve to position the radiator side-to-side and at the back. The front of the radiator is positioned by the cross-member.

- I was waiting for some 1/4" EPDM rubber sheet to arrive from McMaster Carr to make mounting pads, so mocked up the mounts on the radiator using some 1/4" wood bits to determine the spacing of the mounts to get a good fit of the side tabs to the radiator. You can also see here that at this point I needed to trim the back tabs a little so that they don't interfere with the rubber flaps at the bottom of the shroud. I also realized that the parts had some bow on the wide flat surface which tends to happen when using a section cut from tube. I worked out the bow with a hammer and dolly after this photo. Probably would have been easier to make them from flat sheet and make the extra couple of bends!

- Once the rubber pad material arrived, I made the rubber pads and double checked the desired spacing of the mounts to attach them to the frame cross member. Then welded the passenger side mount to the cross-member. You can also see how the grill attaches directly to the frame cross member top in this shot.

I didn't weld the driver side mount yet. It sits over the steering shaft tunnel in the cross member with plenty of clearance, but I'll need access to final fit and weld the steering shaft tunnel tube in the cross member after the engine and steering shaft are positioned. So I'll weld that rad mount after finishing the steering tunnel. In the meantime, I made a cheesy temporary clamping of that mount to hold the radiator to mock up the engine position later.


- The next pic show the rubber pad for the rad mount. I like the material, but the way that I made the tab sections of the pad didn't work that well, so I may change it. I made a template and cut out the rubber parts. At the inside corners I used a leather punch to make round punched corners so It would be less likely to tear. Where there's a screw head on the bottom of the radiator, I punched a hole to clear the screw. For the tabs, I scribed cuts about half way through on the underside - where the lines are marked on the templates. These allow the pad to fold upward at the cross member and tabs. This worked OK, but they like to spring back and are awkward to position on the mounts, so I may change it. I’m thinking I may just cut separate parts and attach them to the mounts with an adhesive or gasket maker RTV. Details, details...

Front Axle

The front Dana 44 housing was built by the R&P shop in Oregon. Great folks, and really helpful. I think the business now solely does full builds rather than components. Their approach to the front Dana 44 housing is cool - they use a rear center section and mount new C's. There is no cast spring pad on the housing center section top or bottom as is often the case on front D44's. I like that approach as it's very flexible in configuring the suspension. It's a little bit of a challenge to mount the passenger side spring perch, since the CJ rail spacing and YJ springs mean the perch needs to overlap the end of the center casting. R&P also set-up the ARB and gears, and I added the axles and outers. Discussion with R&P and feedback from forum members lead me to go with CJ wide track width to gain more turning tire clearance than the original narrow track.

At this point, my plan was to re-use the original '53 "narrow track" D44 rear axle that I had built up previously. It was set up with 4.27 gears, an ARB locker, and Summers Brothers Full-Float axles. I also initially planned to use 33's that I already had. With those tires, I figured that the 4.27 ratio would provide an all around balance in off-road and on-road performance. The 4.27s with the Warn OD would work nice for the road , while the lower 6.32 first gear of the Ford T-18 gains a much lower crawl ratio than the original T-90 2.79 first and 5.38 axles. With that initial plan for reusing the rear D44 and 33's I already had I had the new D44 front set up with matching 4.27 gears. (Later on I revisited the rear axle and tire decision... more on that later as the plan evolved...)

Dutchman made the front axles, and they look great. For the front axle outers, I went with APM Chevy style flat top knuckles. I'm using SUA leafs and am not setting up for a high steer - so why get flat tops? Well, I needed knuckles, i figured there was no harm in having steering options for the future, and the fresh APM castings are nice overall. The YJ springs and my steering box position support the longer arm of the Chevy Style Knuckles (vs shorter Dana 30).

Here's some pics in order of the following notes:

- Axle housing, and APM knuckles with ball joints I installed with my new ball joint tool ( A new thing for me, having only worked on Dana 27 king pins at that point! )

- Knuckles installed

- Trimmed Chevy spindle. Assembly went smoothly until I was mounting the Warn hubs... and they didn't fit right. I'm using "small bearing" Chevy truck spindles, Ford 5 on 5.5" hubs and rotors, and Chevy caliper brackets and calipers. This combo has been documented in several posts / web sources. The set up uses internal splined locking hubs. When I went to mount the Warn hubs, the large outer snap ring would barely snap in place, and there was no free play for the warn hub body to float behind the snap ring. The smaller axle snap ring also was an issue. The latter was easy to address- I just pried the axle outward and then the axle snap ring would just fit. The outer snap ring was more of a concern. The Warn instructions say to check the hub fit to assure some free play, and if there's a problem they suggest adjusting the wheel bearings again and to also make sure the inner bearing nut pin is fully engaged in the mating lock ring hole. I checked both, resetting the bearing adjustment, and still had the problem. Measuring the lock nut, spindle tip, and warn hub body depths, it seemed more likely that the inner splined section of the Warn hub was bottoming out on the end of the spindle, rather than the outer body casting hitting the bearing adjust lock nut. I took the lock nut off and the hub body stayed in the same position- no free play. This confirmed that the spindle was hitting the center section of the warn hub, and the problem was not the bearing adjust lock nut.

There was about 1/8" of exposed threads on the spindle beyond the lock nut when the bearings were properly adjusted, and some of this is a lead-in taper, so there was room to trim the spindle tip to gain clearance for the hub. With the hub bottomed out, the snap ring would snap partially into the groove, so the spindle didn't need much trimming. The spindle is too big for my little lathe chuck so I used a grinder followed by leveling with a mill file, and a little thread chasing using a needle file. The spindle mounting surface-to-tip distance was initially 6.055". I reduced it by 0.055" to 6.00", The pic shows original height (in front) and reduced height (in back) Final assembly confirmed that the fix worked.

- Assembled axle

- Then prepped and welded Ballistic Fab spring perches for front and rear axles. This pic shows the prepped part prior to weld. While the front axle housing has 2.75' tubes , I went with the 2.5' tube size perch. The 2.5" tube part number has a shorter (4.6") overall length than the 2.75 part. I want the short perch to reduce the length of spring constrained by the perch against the spring plate - to minimize spring constraint to maximize droop distance. I changed tube opening of the perch to match the 2.75" tube diameter and also cut it deeper into the perch get the spring as close to the axle as possible while leaving sufficient spring pin clearance with the axle tube - a little help for ground clearance at the spring plates.

- For the front passenger side, the perch needed to straddle the center casting. One option is to just cut a bigger radius on the perch to match the casting radius and weld it to the casting-but I prefer to keep all of the welds on the steel tube. Another option is to make an offset perch similar to the old dana 27, that only welds to the tube. After kicking some ideas around through forum feedback posts I came up with the design shown on the right in the last photo. Ballistic Fab perch on left, Fabbed passenger side perch on right.





More details on the passenger side front perch in the next post...

So glad to see this thing pop up here! Super clean work!! Are you a tooling guy by trade?

Really nice work. Need to look at this on a bigger screen than my phone.

Thanks Simple’72CJ! I've thoroughly enjoyed your build posts . I really admire your work - remarkable fab, especially your welding skill! Wow!

On my jeep fab stuff I’m getting better at it as I go along. The first engine swap I did years ago was pretty hacked work, but I'm getting better at it with time. Career wise, I'm retired now, but was in manufacturing engineering, design engineering, and management in medical electronics - mostly in the making of ultrasound transducers which have interesting fab processes for making proprietary tiny stuff!

Thanks white-rhino! I really appreciate your comments! Lots more pics coming...

Front Diff Spring Perch

As described previously, I wanted to make a perch for the passenger side that would be welded solely to the housing tube while extending under the outer end of the cast housing to align correctly with the spring. Received some good ideas from forum members on this perch design question. One idea was to make a solid one cut from a block. Another is to just fab a similar shape from plate. But the tricky part is those approaches is that they didn't provide a way to make an axle tube weld along the axle tube on the center housing side of the perch, while also mocking it up to tack in place at the final pinion angle. The final design solved those concerns. Here's the some step by step pics and explanation in the order of the pics:


- The first pic is the final part. ready for welds.

-The next photo shows the perch base and angled upright blanks after forming. Both are 1/4" plate. In forming the upright, I rough bent the ends, then made minor bend increases until I got the alignment to the corners of the base the way I wanted. I checked to keep the bends equal on each side as the angle was tuned for fit.

- The third pic shows slots and spring pin holes added in the base part. Drilled the spring pin hole and starter holes for slots in the base. The slots will accept two tabs that locate the angled upright to the base. The slots were then cut with a jig saw, and filed to finish. A round chain saw sharpening file was handy to finish up the slot ends. I was originally going to drill three spring pin holes, based on a forum member suggestion, to support axle position tweaks if needed later. I also originally thought I would place a long single tab slot at the center. But the spring pin hole edge and the inside tab edge needed to be essentially in-line in order to get the perch positioned correctly along the axle to align to the springs. to address that concern I went with two tabs spaced apart with a single spring pin hole well separated from the tab welds.

- Tabs were then made on the bottom side of the angled upright. This shows the initial rough cut.

- Finished tabs. The tabs and mating lower edge of the angled upright part were detailed with files. This tabbed approach solved the weld access issue described at the beginning of this post. The tabs and slots will hold the parts aligned together without welding so they can be clamped in position on the axle tube to set the final pinion angle (later when the rig is at full weight). The tabbed design allows the perch to be fully welded to the housing tube (not the cast housing) while being positioned on the tube directly against the edge of the diff casting. The final weld sequence is: 1) Assemble the perch on the axle and springs clamped with the U bolts to position the perch to set pinion angle. 2) Tack the corners of the angled upright to the axle tube. 3) Disassemble, leaving the angled upright tacked in place. 4) Weld the angled upright part to the axle tube along the whole perch to axle tube joint. This weld line faces the interior of the perch when the assembly is completed 5) Weld the perch base to the angled upright at the mating slots & tabs as well as weld the interior corners as much as can be accessed next to the axle tube 6) Weld the outer side of the perch to the axle tube. 7. Weld perch end caps to the perch and axle tube. 8) level the tab welds on the base to smoothly contact the leaf spring.

- Tube cradles and end cap fit. With the tabs fit to the base, I then laid out and cut the axle tube cradle on the upright. This assured that both tube cradles were aligned well to each other. I learned this sequence the hard way: the first upright I made I had cut the tube cradle first, then cut the tabs...and the cradles didn't align well. Much easier to mark the upright tube cradle cut referencing the base part cradle position with a combo-square, AFTER the tab joint was done! I also laid out and cut the ends of the base and upright for the end caps. This pic shows the tube cradle and end piece cuts added. In addition to the jig saw, I also used a bench grinder and file to clean up the curve fit of the tube cradle and to gradually shape the sloping end cap fit on the bent sections of the upright. The pic shows the finished matching tube cradle and end cap cuts.

- Perch end caps. This pic shows the end caps This overall perch size and shape matches the three Ballistic Fab perches used elsewhere. Since I had one set of perch parts left over from the four I ordered, those were used and modified to fit.

- Fit adjustment. At this stage I fit the perches up on the axle and springs, and found that there was still a slight interference with the housing casting. Rather than shave the housing, I modified the base of the perch, making a small notch for clearance at that point, with some allowance for rotation in final positioning for pinion angle.

- Chamfered the tab slots for full weld penetration. This was another final refinement. Cut the slot chamfer with a burr.

- Trimmed weld tabs. The weld tabs were trimmed a little to align the end of the tab with the bottom of the slot chamfer . This also supports good penetration, and also reduces the amount of weld protrusion that will need to be leveled off for smooth contact of the perch base to the leaf spring.


This little perch has been a lot of work, but I think it will work well.

Spring Mount Concern

At this point, the main leaf of each RE leaf spring was mounted along with a dummy block filling the space of the other leaves, so I could check full stuff and droop articulation. I also wanted the axles in place to start mocking up the drivetrain.

At this point, I was planning to mount the axles with square U bolts, fabbed flat bottom plates, and GM truck brackets on top - "flip kit" style.
The photo shows the mocked up flip kit style axle mount, stuffed to about flat spring level. I wasn't too happy with this spring mounting approach. Even with the u-bolts trimmed, the GM caps and tall nuts consume a lot of space above the axle. While it's nice for improving ground clearance at the underside of the spring mount vs a conventional U bolt & spring plates, I didn't like the reduced top side clearance at stuff. When articulated side to side, the nuts at the stuff side rise even higher from the angled axle, so bump stops would need to limit travel to stop lower than what is shown here. I decided to change the spring mount approach. While I pondered the alternatives, this initial mock up was good enough to start drivetrain layout, so I moved to that. I'm happier with the spring mounting approach I later decided on, and will discuss it in later posts. On to drive train layout...

One of my favorite builds from the other site. Glad to see you over here!

CJ3BL said:

Front Diff Spring Perch

As described previously, I wanted to make a perch for the passenger side that would be welded solely to the housing tube while extending under the outer end of the cast housing to align correctly with the spring. Received some good ideas from forum members on this perch design question. One idea was to make a solid one cut from a block. Another is to just fab a similar shape from plate. But the tricky part is those approaches is that they didn't provide a way to make an axle tube weld along the axle tube on the center housing side of the perch, while also mocking it up to tack in place at the final pinion angle. The final design solved those concerns. Here's the some step by step pics and explanation in the order of the pics:


- The first pic is the final part. ready for welds.

-The next photo shows the perch base and angled upright blanks after forming. Both are 1/4" plate. In forming the upright, I rough bent the ends, then made minor bend increases until I got the alignment to the corners of the base the way I wanted. I checked to keep the bends equal on each side as the angle was tuned for fit.

- The third pic shows slots and spring pin holes added in the base part. Drilled the spring pin hole and starter holes for slots in the base. The slots will accept two tabs that locate the angled upright to the base. The slots were then cut with a jig saw, and filed to finish. A round chain saw sharpening file was handy to finish up the slot ends. I was originally going to drill three spring pin holes, based on a forum member suggestion, to support axle position tweaks if needed later. I also originally thought I would place a long single tab slot at the center. But the spring pin hole edge and the inside tab edge needed to be essentially in-line in order to get the perch positioned correctly along the axle to align to the springs. to address that concern I went with two tabs spaced apart with a single spring pin hole well separated from the tab welds.

- Tabs were then made on the bottom side of the angled upright. This shows the initial rough cut.

- Finished tabs. The tabs and mating lower edge of the angled upright part were detailed with files. This tabbed approach solved the weld access issue described at the beginning of this post. The tabs and slots will hold the parts aligned together without welding so they can be clamped in position on the axle tube to set the final pinion angle (later when the rig is at full weight). The tabbed design allows the perch to be fully welded to the housing tube (not the cast housing) while being positioned on the tube directly against the edge of the diff casting. The final weld sequence is: 1) Assemble the perch on the axle and springs clamped with the U bolts to position the perch to set pinion angle. 2) Tack the corners of the angled upright to the axle tube. 3) Disassemble, leaving the angled upright tacked in place. 4) Weld the angled upright part to the axle tube along the whole perch to axle tube joint. This weld line faces the interior of the perch when the assembly is completed 5) Weld the perch base to the angled upright at the mating slots & tabs. 6) Weld the outer side of the perch to the axle tube. 7. Weld perch end caps to the perch and axle tube. 8) level the tab welds on the base to smoothly contact the leaf spring.

- Tube cradles and end cap fit. With the tabs fit to the base, I then laid out and cut the axle tube cradle on the upright. This assured that both tube cradles were aligned well to each other. I learned this sequence the hard way: the first upright I made I had cut the tube cradle first, then cut the tabs...and the cradles didn't align well. Much easier to mark the upright tube cradle cut referencing the base part cradle position with a combo-square, AFTER the tab joint was done! I also laid out and cut the ends of the base and upright for the end caps. This pic shows the tube cradle and end piece cuts added. In addition to the jig saw, I also used a bench grinder and file to clean up the curve fit of the tube cradle and to gradually shape the sloping end cap fit on the bent sections of the upright. The pic shows the finished matching tube cradle and end cap cuts.

- Perch end caps. This pic shows the end caps This overall perch size and shape matches the three Ballistic Fab perches used elsewhere. Since I had one set of perch parts left over from the four I ordered, those were used and modified to fit.

- Fit adjustment. At this stage I fit the perches up on the axle and springs, and found that there was still a slight interference with the housing casting. Rather than shave the housing, I modified the base of the perch, making a small notch for clearance at that point, with some allowance for rotation in final positioning for pinion angle.

- Chamfered the tab slots for full weld penetration. This was another final refinement. Cut the slot chamfer with a burr.

- Trimmed weld tabs. The weld tabs were trimmed a little to align the end of the tab with the bottom of the slot chamfer . This also supports good penetration, and also reduces the amount of weld protrusion that will need to be leveled off for smooth contact of the perch base to the leaf spring.


This little perch has been a lot of work, but I think it will work well.

Click to expand...

it's amazing how much time and thought and work can be put into something as "simple" as a leaf spring perch.

Engine Prep

As the first step in mocking up the engine bay and drivetrain layout I've got some prep work to do on the engine itself so I can assess clearances with the main engine accessories in place. The GM 4.3 engine is a new old stock Goodwrench Crate motor I got at a nice price from a dealer. It's a one piece rear seal, roller cam, non-balance shaft long block. started getting additional parts for the engine gathered up and installed with the priority on those that can pose a positioning concerns in firming the layout. Here's some of the easy bits and pieces:

-I chose to run a short nose chevy small block/V-6 water pump to keep the overall length compact. In changing to the short H2O pump set-up, I was concerned about the stock harmonic damper as it's protruding outer lip limits pulley choices, and I think it's depth is more appropriate for a long pump. The first pic shows the original stock damper

-Chose a Fluidampr unit. I researched 4.3 balancing, and as best I can determine the original harmonic damper on mine does not have balancing features, and the external balancing of the engine is achieved with the correct flywheel. I had already purchased the Centerforce flywheel that is spec'ed for the engine: "1986 and up-Chevy 4.3 V-6, 305,350 V-8, 168 tooth ring gear. Billet steel 168 Tooth GM/Chevy flywheel for use with 1986 and newer (non Gen3) engines with 1 piece rear main seals. (correct EXTERNAL balanced counterweighted flywheel), 35Lbs., 14' diameter, SFI 1.1 safety rating. Goodwrench engine instructions with the engine purchase specify GM # 10105832. Later GM info shows equivalent replacement part is GM #14088648. Same specs as above- 14”, 168T, external balanced, 3” bolt pattern. Inspecting the Centerforce part confirmed it has drilled balancing holes on its back side, which further confirming my thinking that the correct damper doesn't provide the external balancing of the engine, and I had chosen the right Fluidampr part # FLU620101. I removed the stock damper and installed the Fluiddampr using a puller/installer tool. With the new damper in place it was clear that the old pointer on the timing cover would not work well as its markers protruded beyond the new damper- which not only wouldn't provide readable timing indication, but would also prevent the pulley from being mounted. So I pulled the damper and timing cover off, removed the pointer and welded the holes closed. Chose a new separately mounted Moroso pointer. The pic shows the patched cover, new timing pointer, and Fluiddampr reinstalled.

-Short water pump installed:. This an Edelbrock pump, EDL-8810, short, standard rotation for v belts. Need to sort out brackets for power steering pump and alternator and pulleys. While doing that I moved to fitting the bell housing...

- Bell Housing and slave cylinder. I'm using a Centerforce CF700160 GM flywheel , CTFC165552 GM pressure plate (11") and CTFC281226 Ford clutch disc (11” with 1 1/16” 10 spline input) , Advanced Adapters 716193 adapter pilot bushing to mate with the Chevy Flywheel and Ford T18 transmission, and
Advanced Adapters 712548 bell housing. The bell housing fits the 14'' GM flywheel, and has built in mounting holes for the Jeep slave cylinder that was used on the 80-83 Jeeps Cj with the "Iron Duke" GM 4 Cylinder. (interestingly, I already had a smaller bell housing from my early Pontiac "Iron Duke" swap. While it fits the 4.3 V-6, it only fits a smaller flywheel, so I sprung for the AA so I could run the 14". It's nice to have the mounting holes on the housing except that the slave didn't quite fit. The slave ear overlapped the lower corner of the block. I ground a very small flat on the lower corner of the block and a larger flat on the slave cylinder boss to get it to fit. There's plenty of material remaining. The pic shows the fit of the tweaked slave cylinder. Note: much later in the build, the slave cylinder was changed to a Tilton internal slave as the tip of the throw out arm was too close to my gas pedal foot. More on that later...