My Juggy Build

[Eric]

I first started spending $ on this project 7 years ago and the build itself started about 3 years ago. Now that the project is almost finished I figured it was time to start a build thread!

My goal from the start has been to build a capable and reliable trail rig that maintained the full-bodied Jeep look. I have no interest in racing or keeping up with tube buggies and various design decisions have been made accordingly.

Although the end product will look like a Jeep I’m posting this thread to General 4x4 instead of Jeep because the only Jeep in this project amounts to some sheet metal skin.

Key Spec’s

• Motor: 2001 GM 5.3 truck motor (LM7), bored 0.020”, Comp Cam, F-body intake & accessories.
• Transmission: Hughes Performance Turbo 350, full manual valve body, compression braking, 1500 rpm stall, 850 HP rating
• Transfer case: Altas 2 speed, 4.3:1 low range
• Front axle: 1995 Ford Dana 60 front housing w/ ’02 Super Duty knuckles, Grizzly locker, 5.38 gears, RCV 35 spline shafts, PSC full hydro steering
• Rear axle: 2002 Ford Dana 60 from Super Duty van, Grizzly locker, 5.38 gears, Branik 35 spline alloy shafts
• Front suspension: 3 link w/ panhard bar, 14” King coilovers, Fox 2” air bumps
• Rear suspension: Double triangulated 4 link, 14” King coilovers, Fox 2” air bumps
• Tires & Wheels: 39.5x13.5x17 BFG red label Krawlers on 17x9.5 Raceline beadlocks (summer/rock crawling)
• Tires & Wheels: 39.5x13.5x17 Super Swamper IROK bias on 17x9.5 Raceline beadlocks (everything else)
• Other: Custom built frame and roll cage skinned with various bits of Jeep sheet metal

As of July 2022 the project was trail ready (although still not "finished"). The photo below shows how the project sits as of Sept 2022:

The chassis has been modeled in Solidworks and includes appropriate kinematic joints so that the suspension can be digitally flexed to check for interference. My goal was to manufacture the chassis within 1/8” and 1 degree of the as-designed geometry and this goal has been largely achieved.

Here is a video walkaround of the more-or-less completed rolling chassis:




Going forward I will add posts that detail key areas of the project including frame, cage, motor, suspension, and axles.

Stay tuned!

 

[arse_sidewards]

Are you gonna weld the portions of body/frame with the vin plates from a Jeep you own to it? Not a lot of wheeling around here for vehicles that can't drive themselves to the "trail"

 

[TiTRD]

Are you gonna weld the portions of body/frame with the vin plates from a Jeep you own to it? Not a lot of wheeling around here for vehicles that can't drive themselves to the "trail"

That is 100% a false statement. Just need to get in the right circle. OP can get you started ;)

Looks good, Eric.

 

[Eric]

That is 100% a false statement. Just need to get in the right circle. OP can get you started ;)

^ Correct statement. We may not have public land or many open-to-the-public OHV parks here in the Northeast but we more than make up for that with private properties legally accessed through club relationships with landowners. For example, the RI-based clubs that I belong to have access to no less than 8 private properties within an hour drive. Two of them are within 3 miles of my house and I could easily drive an unregistered buggy to both since my town does not have a police department.

 

[arse_sidewards]

That is 100% a false statement. Just need to get in the right circle. OP can get you started ;)

I know there's private club trails but there are tons of unmaintained roads and ungated power/gas line/logging roads in all of New England that you can't park a tow rig at and can't drive an un-plated vehicle to. Not that you can't always add VIN bits later but it seems kind of silly to limit yourself. Being street legal also opens you up to being able to take "I gotta drive to X to run errand Y so I might as well drive the rig and do a lap on trail Z while I'm nearby" type of wheeling.

 

[Eric]

The next five posts describe construction of the frame. The photos span almost 3 years!

This build actually started outside in my yard. One of these years I will build a shop. In order to keep things level and square I built a frame table using steel from the scrap yard.

Plan A was to build off a TJ frame which I bought for $300. Anybody who is familiar with TJ frames in the Northeast knows that they rust away from the inside out. This particular frame seemed to be in decent shape. The rear section, especially around the factory control arm brackets, was rusted but I was going to cut the back off anyway and replace with an Artec back-half kit. Since the front axle was going to be moved forward I was also planning to cut off and raise the front section of the frame to aid up travel. While grinding brackets off the frame I noticed that the lower section where the factory skid plate bolts on was getting very thin so I started cutting the bottom of the frame off with a plan to replace with a patch.

It was at this point, grinder in hand and pissed off, that the awakening happened. Build a fawking frame from scratch you dumb ass!

 

[Eric]

Sticking with the original goal of maintaining a full-bodied Jeep look the decision was made to closely match TJ frame dimensions, especially in the mid section where the body mounts are located. This is also where CAD first entered the picture.

I’m a mechanical engineer by degree and have spent the last 25+ years developing the Abaqus finite element software. Up until this point my CAD skills basically amounted to creating a flat plate with a hole. Some years ago the company I originally started working for was acquired by Dassault Systems which also develops CATIA and Solidworks so I said fawk it, let’s learn CAD! Corporate IT set me up with Solidworks and I spent the next 6 months or so learning the program by modeling the frame and various other components such as the motor, axles, suspension, etc, etc. The intent behind modeling the motor and axles was to create representations that were accurate enough for digital mockup. Eventually, I ended up with a model that included the frame, motor, transmission, transfer case, axles, suspension, tires, and roll cage. The model provided some assurance that everything would fit without interference and also provided most of the numbers needed for the suspension calculator. The images below show just the frame sub-assembly including some tube work that is welded to the frame (to be discussed later). I will make the CAD files available in case anybody wants to reuse them.

 

[Eric]

Time to start building! The majority of the frame was constructed from 2.5” x 4” tube which matches the factory TJ size. The back half was constructed from 2” x 3” tube and was mated to the front half using a kit from Artec. Wall thickness of the tube is 0.188” so its considerably more beefy than a stock TJ frame. Bracketry and so forth is a mixture of off-the-shelf components and custom where off-the-shelf was not available or would require significant modification. Off-the-shelf parts include the Artec back-half kit, Genright body mounts, Ballistic Fabrication front upper control arm brackets, and Barnes 4WD winch plate. Most of the other parts including rear suspension brackets, track bar brackets, motor mounts, fish plates, and so forth were exported from the CAD to .dxf files and cut by RI Water Jet.

As mentioned previously, the build started outside in my yard. Here the mid and back sections of the frame are being fit together and tacked. I made liberal use of clamps and "temporary" cross members to keep things square and minimize distortion during welding.

 

[Eric]

A short time later I started renting some space from a wheeling buddy who was looking to share expenses on a unit he was leasing. Literally a month after moving in we got evicted but my buddy quickly found a new building and carved me out a place to continue working. The following photos show the front section of the frame in place along with fitting of body mounts and motor/transmission tabs. I used a mockup block with heads and an empty Turbo 350 housing to get the fitment correct.

The rear suspension crossmember design was shamelessly borrowed from Genright with some tweaks to fit my specific application.

The crossmember shown in the photo below is located under the transmission and primarily serves as a place to mount the belly skid plate. This crossmember can also be used for link mounts if, in the future, I decide to switch the front suspension from 3 link w/ track bar to double triangulated 4 link. Also shown in this photo is part of the transmission/t-case mount which will be described in a separate post.

 

[Eric]

By November 2019 the build was starting to accelerate and more space was needed to spread out so I started renting my own shop.

The photos below depict the completed frame sub-assembly which weighs in at a svelte 460 pounds.

 

[Eric]

It’s been 4 months. Time for another update. The next several posts will cover the motor and transmission. Most of the work shown here dates back almost 3 years. Nothing particularly ground breaking.

I started with a 2001 5.3 Vortec (LM7) and a Turbo 350 attached to an NP 203 that was purchased for $400 from a buddy who abandoned his own project. The plan was to rebuild the motor and transmission and sell the 203 to somebody looking to build a 203/205 doubler.

 

[Eric]

Step 1 was to disassemble and label the parts. The only parts being reused from the motor were the block, crank, rods, and head castings. Everything else was replaced.

The parts were shipped off to R Johnson & Sons in Warwick, RI for cleaning and machine work. The cylinders were bored 0.020” over, block and cylinder heads were decked, new pistons were installed, crank journals were checked and polished, rotating assembly was balanced, Competition Cams XFI extreme truck camshaft was installed, and heads were bead blasted then fitted with new valves and springs.

 

[Eric]

The motor was converted to F-body (LS1) intake and accessories in order to shrink the package a bit. An LS1 intake w/ injectors was sourced from GM Performance as was the H3 oil pan. The H3 oil pan shaves off about 3/4” in depth compared to the stock truck oil pan. In retrospect I should have gone with the F-body oil pan which shaves off over 2 1/2” in depth compared to the truck oil pan. The accessory bracket came from Goat Built and is specifically intended for use with CBR steering pump because P-pump does not fit with F-body accessory spacing. The Sanderson headers came from Novak conversions and are intended for Jeep LS conversions. Heater hose ports in the water pump were tapped and plugged.

 

[Eric]

Next step was to bolt the motor together. I did not take any photos but it was something of a pain in the ass to get the push rod length dialed in. Valve train on the Gen III LS motors with stock-style rockers is not adjustable so you have to measure the pushrod length that is needed to get the proper lifter pre-load. This is especially true when the block and heads have been decked.

I’m not particularly thrilled with how close the passenger side header is to the starter but I know a couple guys running the same headers who report no problems overheating the starter.

I tried the mason line trick to size the serpentine belt but still needed to make a couple tweaks to get the right size belt.

 

[Eric]

I decided to run a Turbo 350 because it’s short and, most importantly, does not require any wires. Plan A was to rebuild the Turbo 350 myself and convert it to full manual. I rebuilt a Torqueflite 727 many, many years ago and figured why not give it a shot. About 20 minutes into disassembly, I ran up against the first snap ring that was buried in some hole. Fawk this. I was on the phone with Hughes Performance the next day and they set me up with a built Turbo 350, full manual valve body, compression braking, and all the strength upgrades rated for 850 HP (part number 35-2CX).

The torque converter stall speed is a fairly low 1,500 rpm because this is primarily a crawling rig.

The Turbo 350 bolts to the LS block but the LS crank stick out is less than the old school small blocks thus a special spacer is required to support the torque converter snout. The holes on the LS flex plate also need to be redrilled to fit the Turbo 350 torque converter. Advance Adapters makes a kit (# 712500A) that includes the required flex plate and spacer.

 

[SLOWPOKE693]

I'm glad to see this build being posted, the teaser pics posted over the years have been killin' me!

Looks like you are building it similar to the way I built Drew's LJ. A buggy with a Jeep body wrapped around it. I love it!

Great choice not using any of the stock frame. That was the one thing I wished I had done when I built his. The 3-4ft of stock frame i left in there ended up being more of a PITA to work with than it was worth. It was hard to convince him that the LJ frame with only 17k miles on it needed to go completely away, so I used part of it. Meh.... Live and learn.

 

[Eric]

. . . Looks like you are building it similar to the way I built Drew's LJ. A buggy with a Jeep body wrapped around it. I love it!

Definitely took inspiration from Drew's rig. Nice piece of work. I really liked the tube work where the tailgate was located and was torn between doing something similar or fitting a CJ tailgate. I ended up doing a CJ tailgate. I know its going to get fawked up but I will get some poser photos first.

 

[Eric]

The next three posts cover the axle assemblies. Suspension details will be covered in a later post. The rear axle is a Dana 60 from a 2001 Ford E-350 Super Duty. This axle was chosen because of the smooth bottom center section, large and thick tubes, and factory disc brakes. The front axle is a hybrid 1995 F-350 Dana 60 housing with 2002 Ford Super Duty knuckles. I went with this combination because the earlier pre-Super Duty housing has more tube to work with on the driver side and I like the convenience and simplicity of unit bearings. At one point I had a 2006 Super Duty front axle in hand but was not thrilled about cutting off the cast-in radius arm brackets. In retrospect I should have stuck with the ‘06 axle because of the more robust unit bearings.

Step 1 was to strip the axles and get them sandblasted.

 

[Eric]

This post covers the rear axle build. I’ve been a fan of Detroit lockers since my first wheeling rig way back in the early 80’s but the folks at Randy’s convinced me to “upgrade” to Yukon Grizzly lockers. Several wheeling buddies have been running Grizzly’s so I figured why not. The 5.38 gears were also supplied by Yukon. The stock axle shafts were ditched in favor of 35 spline alloy shafts and drive flanges supplied by Branik Motorsports. The factory spindle nuts were replaced with Stage 8 X-Locks which don’t loosen in use. The keyway on the E-350 spindles is apparently a bit more narrow than other Dana 60’s which necessitated a slight customization of the X-Lock system.

The truss and other suspension brackets are all custom as driven by the suspension design. Since this is a trail/rock crawling rig the gear setup was intentionally targeted to be a little deep which is a slightly stronger way to run gears. The rear axle assembly complete with factory brakes weighed in at a paltry 422 lbs.

 

[Eric]

This post covers the front axle build. The main components include a full hydraulic steering kit from PSC (# FHK400P w/ 2.75” x 8” cylinder), an Artec hydraulic cylinder mount, RCV shafts, high steer arms from Weaver Fabrication, Timken unit bearings from Branik Motorsports, Alloy USA stamped cover, and Yukon Hardcore locking hubs. The folks at RCV set me up with a hybrid shaft combo consisting of the early ‘90s Ford inners and ’99-’04 Super Duty outers. Branik redrilled the unit bearings to match the rear axle’s 8 on 6.5” bolt pattern and also broached the center to fit 35 spline shafts. I originally started with a Solid Axle diff cover but it interfered with the steering cylinder. The Alloy USA cover is stamped from 5/16” steel which provides plenty of beef along with the necessary clearance.

I wanted to run the steering links in double shear for added strength and also for the extra degree-of-freedom to line up the steering links with the hydraulic cylinder. Achieving this required some custom machine work because the Weaver high steer arm is offset and angled slightly different than the factory.

The remaining brackets were all custom made as driven by the suspension design. The front axle assembly complete with factory brakes weighs in at 583 lbs.

Upon installation the Yukon locking hubs did not engage and disengage correctly. There is a thrust washer and some other washers inside the stock unit bearing assembly which do not fit over 35 spline shafts. According to the folks at RCV these washers are not needed because RCV shafts are “self centering”. The hubs include a spacer that stacks on top of the factory washers and I think the problem with the hubs is that the spacer supplied with the kit relies on the thickness of the factory washers. I have tried calling Yukon a few times but no call back yet. In the mean time I picked up some front drive slugs from Branik. If I can get the hubs working then I will use them and keep the slugs for spares. Otherwise I will run the slugs.

 

[Eric]

Next topic is the roll cage and front tube work. Most of this work was done two years ago over the Christmas break. I wanted the cage to have a certain style, enough structural integrity for the intended purpose, and to be easily removable for periodic teardowns and maintenance. There are a few places where I deviated from “proper" node best practices in favor of aesthetics, access, and visibility. I don’t think any of these compromises significantly impact structural integrity for a rock crawling trail rig that might see the occasional flop.

All of the tube work was first modeled in Solidworks. From there it was easy to extract all the points needed to recreate the design in BendTech Pro. IMO, the tube notching templates alone are worth the price of BendTech. The bend order instructions are also useful, especially when bending pieces that will not be planar (i.e. tube fenders).

The cage is attached to the frame with flanges at the a, b, and c-pillars. The photos below depict fabrication of the frame-side attachment points. I spent quite a bit of time building scaffolding from angle bar and so forth in order to precisely locate all six attachment points within 1/8” of the as-designed positions.

 

[Eric]

With the frame side attachment points tacked into place the next step was to flesh out the primary cage structure consisting of continuous a-c pillars and four transverse separators. All key style elements I was going for are captured by the a-c pillar. First, there is a slight upward rake from the a-pillar to b-pillar. I like that look and on the practical side it creates more headroom. At the b-pillar the cage is about 2” taller than a TJ hardtop. Second, from the b-pillar the cage tapers down to a short c-pillar for the “fastback” look. Lastly, the a-c pillar is smooth with no protruding b-pillar to get stuck when sliding past obstacles.

At first, I had doubts about the accuracy of the bend order instructions coming from BendTech so I also calculated the bends using the old-school method of drawing the centerlines out full-scale on a large white board. You can never be too careful. I especially did not want to fawk up the a-c pillars which are about 15’ long with four bends.

With the primary structure in place the next step was to fit the b-pillar, seat mounts, hip bar, and b-c connection.

 

[Eric]

Add some triangles and a harness bar.

Add some handles. The passenger side “oh shit” handle is attached with a pin. After failing to drill perfectly centered holes for the pin using a drill press I found this nifty “Drill Rite” tool that nails it every time.

Slap on some self-etching primer and Rustoleum satin black. The painting was done inside during March so I saved some brain cells by brushing instead of spraying.

 

[Eric]

The last major tube work consisted of the obligatory grill hoop, stinger/winch protector, and under hood tube for mounting the coil overs and various other accessories.

 

[arse_sidewards]

I'm a big fan of just brushing paint on stuff that's gonna get beat. Sure it doesn't look as nice but when you do it that way all the patches don't show.

Also nice axle rack.

 

['84 Bronco II]

The cagework is looking great! What bender and notcher are you using, and what program are you using to make the coping templates? I have my cage drawn up in SolidWorks as well, and I am curious what your process was for taking it from concept to reality.

 

[Eric]

The cagework is looking great! What bender and notcher are you using, and what program are you using to make the coping templates? I have my cage drawn up in SolidWorks as well, and I am curious what your process was for taking it from concept to reality.

Bender is JD2 Model 32 with hydro. All notching was done with a cut-off wheel and grinder. Notchers and hole saws are useless IMO.

The notching templates and bend order instructions are all generated by BendTech Pro which is a software specifically intended for roll cage design. There is a screen shot of BendTech Pro posted above. BTW, BendTech is an Irate4x4 vendor. Click Swag on the main menu and order!

The image below helps describe how I went from Solidworks model to BendTech model. First, all the tubes modeled in Solidworks end at the centerlines as shown by the solid lines in the image below. No notching.

BendTech needs the following information to build a model:

1. Size of tube (i.e. 1.75" x 0.120")
2. Centerline radius of die (i.e. 5.5")
3. Coordinates of points on the centerline of the tube.

There are two types of points: End Points and Apex Points. An apex is the imaginary point where the centerline of two straight sections of tube intersect. If you build the Solidworks model as described above then its fairly straightforward to extract the coordinates of the points needed by BendTech. Once you have all the point coordinates in hand it only takes a matter of minutes to create a cage model in BendTech.

For each tube, BendTech will provide all the manufacturing information that is needed including cut length of the tube, bend order instructions, i.e. start first bend x" from end of tube and bend y degrees, and notching templates which you print out and wrap around the tube. There are lines on the notching template that locate the notch, i.e. locate this template z" from start of bend 1.

From that point, cut the notches, fit everything together, and weld it up. I highly recommend holding off on final welding until most, if not all, of the cage has been tacked together. If you weld too soon then shit will warp and pieces won't fit together properly.

 

['84 Bronco II]

Bender is JD2 Model 32 with hydro. All notching was done with a cut-off wheel and grinder. Notchers and hole saws are useless IMO.

The notching templates and bend order instructions are all generated by BendTech Pro which is a software specifically intended for roll cage design. There is a screen shot of BendTech Pro posted above. BTW, BendTech is an Irate4x4 vendor. Click Swag on the main menu and order!

The image below helps describe how I went from Solidworks model to BendTech model. First, all the tubes modeled in Solidworks end at the centerlines as shown by the solid lines in the image below. No notching.

BendTech needs the following information to build a model:

1. Size of tube (i.e. 1.75" x 0.120")
2. Centerline radius of die (i.e. 5.5")
3. Coordinates of points on the centerline of the tube.

There are two types of points: End Points and Apex Points. An apex is the imaginary point where the centerline of two straight sections of tube intersect. If you build the Solidworks model as described above then its fairly straightforward to extract the coordinates of the points needed by BendTech. Once you have all the point coordinates in hand it only takes a matter of minutes to create a cage model in BendTech.

For each tube, BendTech will provide all the manufacturing information that is needed including cut length of the tube, bend order instructions, i.e. start first bend x" from end of tube and bend y degrees, and notching templates which you print out and wrap around the tube. There are lines on the notching template that locate the notch, i.e. locate this template z" from start of bend 1.

From that point, cut the notches, fit everything together, and weld it up. I highly recommend holding off on final welding until most, if not all, of the cage has been tacked together. If you weld too soon then shit will warp and pieces won't fit together properly.

Sweet, thanks for the explanation! I glossed over the screen shot, but I figured you were probably using BendTech.

I am curious why you say notchers and hole saws are useless though? The cutoff wheel and grinder method always seemed like a bigger PIA to me.

 

[Eric]

I am curious why you say notchers and hole saws are useless though? The cutoff wheel and grinder method always seemed like a bigger PIA to me.

Try it and see for yourself!!

Hole saw is ok for short angles where straight tubes intersect. Once you start notching through bends and complicated nodes then cut-off wheel or plasma is the way to go. I don't know any cage builders who use hole saws.

 

[Mr Stubs]

I'm a big fan of just brushing paint on stuff that's gonna get beat. Sure it doesn't look as nice but when you do it that way all the patches don't show.

Also nice axle rack.

X2 on both.

I brush painted my entire crawler chassis, took forever but at least the paint laid down thick. Sure was cheaper also. I was going to comment on the rack, looks purposely built and very helpful.