Hummer H3 Build

[Ghetto Fab.]

Why not go chromo heat treated? I know Hendrix was making some tie rods from weight lifting bars, the ones where you stack all the 50lb weights on them. Apparently he got them from a friend who would sell that stuff. They were already heat treated chromoly tubing. He would cut them to length and welded bungs on. You could still see the knurling on the bars. I know the Synergy heat treated tie rods take a ton of abuse also.

Aluminum is neat, but has a fatigue life I wouldn't want to deal with.

Kevin

 

[06h3]

Why not go chromo heat treated? I know Hendrix was making some tie rods from weight lifting bars, the ones where you stack all the 50lb weights on them. Apparently he got them from a friend who would sell that stuff. They were already heat treated chromoly tubing. He would cut them to length and welded bungs on. You could still see the knurling on the bars. I know the Synergy heat treated tie rods take a ton of abuse also.

Aluminum is neat, but has a fatigue life I wouldn't want to deal with.

Kevin

HEAT TREAT CHROMOLY 4130 | BENT FABRICATION

Bent Fab's Heat Treated Chromoly 2' x 250 all are the strongest option when you are looking for a suspension link to stand up to extreme 4x4 and desert racing. We custom build them in house to your specifactions. Then have them heat treated.

www.bentfabaz.com

I was checking out this site yesterday. It seems he does that and it’s something I’m considering. My buddy runs heat treated chromoly front lower links and he told me they are in MUCH better shape then his rear mild steel links.

 

[atoz2]

I was gonna ask the same thing. Lol who has a tap? I need 7/8-14 though

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

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decent prices

 

[YotaAtieToo]

Heat treated chomo is a good idea.........



Seriously though, I don't know how it would compare to the stress proof stuff. I'd guess the solid chromo would flex and comeback more, where the HT dom would be more rigid.

You'd have the same issue, kimda, in that you shouldn't weld it. So you have to plan ahead for your ram mount. Or try to move the ram to mount directly to the knuckle or highsteer.

The other option would be a baller double ended assist cyl with a big skid but it's hard to find double ended stuff small enough to work properly with an assist setup.

 

[DMANbluesfreak]

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

decent prices

Not on 7/8-18 (esp LH)

 

[atoz2]

Not on 7/8-18 (esp LH)

oof you are not kidding on that!

 

[06h3]

Started working on the H3 again, I’m in the process of getting more link separation and it made me think.....at what point do people say a 3 link just isn’t enough to control load? 400 hp, double low (5.33:1) 43in tires, closing in on 7k lbs. is a 3 link enough?

I can’t really fit a 4 link.

Admittedly, I never had an issue on 37s, 40s and no issues for a year on 43s....I bent my bracket and until I welded on my new 3 link bracket to replace my bent one I welded it on at way too much of an angle (like 50 degrees) so I only had like 6.5in of separation and at full droop it would lessen itself to like 3. (Suspension did weird shit when I incorrectly mounted it in a rush before my hammers trip)

I currently have 7.5in of separation but can definitely add more up raising the upper. I can probably achieve 8.5-9in before messing with the lower mounts. My lower link mounts are flat with the bottom of the axle tubes, if I cut them off and mount them at an angle below the tubes I can get more.

 

[j20brett]

3-link has been fine for a long time. Heck, it was the go-to suspension for moon buggies for a while as well. Adding separation at the axle is the easiest way to do it, but i would make sure nothing else will be in the way if you start raising it. Have you thrown your links into the 3-link calc yet to see where it sits now, and how moving things would affect geometry?

 

[pennsylvaniaboy]

Started working on the H3 again, I’m in the process of getting more link separation and it made me think.....at what point do people say a 3 link just isn’t enough to control load? 400 hp, double low (5.33:1) 43in tires, closing in on 7k lbs. is a 3 link enough?

I can’t really fit a 4 link.

Admittedly, I never had an issue on 37s, 40s and no issues for a year on 43s....I bent my bracket and until I welded on my new 3 link bracket to replace my bent one I welded it on at way too much of an angle (like 50 degrees) so I only had like 6.5in of separation and at full droop it would lessen itself to like 3. (Suspension did weird shit when I incorrectly mounted it in a rush before my hammers trip)

I currently have 7.5in of separation but can definitely add more up raising the upper. I can probably achieve 8.5-9in before messing with the lower mounts. My lower link mounts are flat with the bottom of the axle tubes, if I cut them off and mount them at an angle below the tubes I can get more.

I have wondered this as well. I have been running a radius arm y-link front for 4-5 years and have no complaints. My dads buggy is about 1k lighter, but about the same build and it has a 3 link...We will see how the longevity diff is.

I do think the link tower a weaker design. The way we built the 3 link is plated the diff with a plate and then added the 3rd link on top of the diff side. It would have to tear alot of weld, versus twist a tower bracket

 

[06h3]

3-link has been fine for a long time. Heck, it was the go-to suspension for moon buggies for a while as well. Adding separation at the axle is the easiest way to do it, but i would make sure nothing else will be in the way if you start raising it. Have you thrown your links into the 3-link calc yet to see where it sits now, and how moving things would affect geometry?

Some things already were and I started moving them lol. I am moving my frame side mount further away from the frame. By doing that it clears up some room for the motor mount. I moved some brake lines and wiring, and may have to trim the motor mount.

Like pennsylvaniaboy mentioned I will probably need to gusset the crap out of the link bracket. It will be pretty tall (probably adding 1-2in on top of the traditional 3 hole 3 link bracket from all typical Barnes, Ruffstuff, etc.)

The other option is to lower the lower link brackets. Which I’m not a fan of right now but still open to it. Right now the links are pretty flat at ride height. That will put them at a steeper angle. I also have the coilover mounts on top of the lower link mounts so I’d have to redo those and lastly they sit in line with the axle tubes. Going lower will make them a hang up

 

[j20brett]

We need pics of current setup. I think im right at 8" separation at axle, 6ish at frame. But, as you said, link angles have a lot to do with how it handles. the flatter the lower link, the better. This is how my 3-link ended up, and im beyond pleased with it. Running center hole on axle tower.

 

[06h3]

My upper link bracket is similar to yours.

Here are my lowers. Ignore the excessive threads. I’m going to be making new links and use FK rod ends. I’m just stretching the wheelbase a little more.

Then the upper I will have to get better pics tonight. Where it’s yellow I plan to cut that out (already cut it a tad) that is where the skid plate mount used to live.

Where it’s purple I can trim back the motor mount and make a base plate to raise the upper link another 1-2in. The current pics are full bump. I would have to strengthen the upper link tower quite a bit if I’m using the top hole and making it taller then it already is.

I’ll have to snap some frame side pics tonight

 

[j20brett]

I looked at my as-built numbers and i ended up with 6.125" separation at the frame, 8.125" at the axle. Trim that motor mount and get 8" at the axle. Then brace the hell outta that axle mount lol.

For the frame end, see if you cant run the bolt all the way through the frame with a sleeve. I had to mount the rod end between the frame and outer part of the bracket, and sleeved the frame. But i have no worries that it'll ever come off.

 

[Lincoln]

The only thing I would suggest is getting the lower mount off centerline. More separation will help but moving the lower will spread the load across the upper and lowers instead of putting most of the rotation force on the upper. Moving the lower an inch down shouldn’t hamper clearance much and help a bunch.

The las one I did looked like j20bretts but I kept one side boxed and add some wings at a 45 from the front edge back.

Mileage may vary. I haven’t built anything like that in 10 years.

 

[06h3]

The only thing I would suggest is getting the lower mount off centerline. More separation will help but moving the lower will spread the load across the upper and lowers instead of putting most of the rotation force on the upper. Moving the lower an inch down shouldn’t hamper clearance much and help a bunch.

The las one I did looked like j20bretts but I kept one side boxed and add some wings at a 45 from the front edge back.

Mileage may vary. I haven’t built anything like that in 10 years.

That made a light bulb go off in my head.

So a certain amount of separation is not equal. Location depends too

 

[DMANbluesfreak]

Yes, the more equally spaced your links are from the axle centerline, the less force they will see in tension and compression. Think about it with an extreme:

Move them 2 feet off the axle centerline (or consider a portal axle). When you do this, both links still see tension and compression cycles, but because they're both connected to a lever arm, essentially, as the axle tries to move forward the lower link (which in this case is still above axle centerline) sees SIGNFICANTLY more tension than if it were below axle centerline. The upper actually sees less compression. The opposite is true in reverse or when braking. Obviously this would affect the vehicle performance, too - but that's not my point here.

I believe this is why factory link setups typically have the lower links pretty far below axle centerline (especially in the rear). On a Jeep and Bronco which is designed for off-road, they move them as close to the hub as possible to limit interference with obstacles off-road.

 

[06h3]

Yes, the more equally spaced your links are from the axle centerline, the less force they will see in tension and compression. Think about it with an extreme:

Move them 2 feet off the axle centerline (or consider a portal axle). When you do this, both links still see tension and compression cycles, but because they're both connected to a lever arm, essentially, as the axle tries to move forward the lower link (which in this case is still above axle centerline) sees SIGNFICANTLY more tension than if it were below axle centerline. The upper actually sees less compression. The opposite is true in reverse or when braking. Obviously this would affect the vehicle performance, too - but that's not my point here.

I believe this is why factory link setups typically have the lower links pretty far below axle centerline (especially in the rear). On a Jeep and Bronco which is designed for off-road, they move them as close to the hub as possible to limit interference with obstacles off-road.

So having the lowers at center line (like they are currently) will put more load on the upper link when moving forward?

 

[YotaAtieToo]

So having the lowers at center line (like they are currently) will put more load on the upper link when moving forward?

Yes, but also, rotating it down doesn't move it off centerline. Separation doesn't have to be only vertical. Think of an Fj80 radius arm. The bushings are directly in front and behind the axle. They often good 300-400k+ mile without issues. Not 100% apples to apples since it's not individual links, but you get the point.

Also, with your mounts off the back, I can see how the lower links act more as a pivot than it does control rotation. Having the old link tower leaned back probably didn't help.

I personally don't see lowering the axle side lower mounts an inch being earth shattering. Maybe if you went straight down it would make a difference, but that's a big compromise.

I'm not sure what I would do if I were you. I'd think a new beefy tower that's not leaned back all wierd would be fine.

You sure you can't fit another upper link in there?

 

[06h3]

Yeah there is no way to fit a upper link in there unless I move the cat and exhaust, lessen up travel and/or change ride height.

I’m fine with moving the exhaust but I need to do that in conjunction with lessening uptravel or ride height which I don’t want to do.

I am thinking this was a freak thing with the angle of my link bracket.

I’m willing to hack off my lowers, lower them 1-2in and make more coilover mounts if the strength gain is there. I don’t wanna do it just to do it. I’d be losing ground clearance and a steeper link angle which I’m not a fan of....I’m willing to make that compromise IF the benefit is there

 

[Lincoln]

……

I personally don't see lowering the axle side lower mounts an inch being earth shattering. Maybe if you went straight down it would make a difference, but that's a big compromise.

I think about it as ratios. If you have 10” of separation and the centerline of the axle is at zero then 100% of the twist is controlled by the upper. If you move the axle centerline up one inch then in stupid engineering I see 9” above and 1” below so guestimately 90% controlled by the upper. To me that’s a pretty big change,

The more overall separation works the same. Go from 10” to 11” and the arms basically have 10% more leverage on the axle decreasing the stress.

I’m sure there are way better ways to think about it but that’s what I have used when thinking about it.

 

[DMANbluesfreak]

^That's a great perspective to think about. And you're totally right - take it to an extreme and put them 5" above/below and each link controls 50% of the twisting. It gets trickier when you move them both above axle centerline, but that's not really practical anyway so we may as well not talk about it.

 

[06h3]

I cut off the lowers, what a fucking pain in the ass that was....I really wonder/hope it’s worth it lol

So my buddy have been talking about 3 link load.

So When you have too little axle side separation It sends load to the frame side and causes frame side issues...right? Not as much axle side stress?

What about frame side separation? Too little causes stress on the axle end?

 

[06h3]

Got the new lowers on and below axle center line. The new separation is 10.25in which I’m stoked on!!!

The new lower control arm angle at ride height went from 5.2* to 9* which I’m not stoked on but gotta get it in a calculator to see if it makes a difference

 

[Lincoln]

Nice. 10 isn’t stupid bad but flatter would be better.

on your question above. Are you asking about the horizontal separation or vertical? I’m missing it. On vertical less separation I’ve only worried about the axle end for strength purposes. Less loads the axle brackets more. The frame end doesn’t seem to matter as much. I think because it’s the leverage end and not producing the torque.

On horizontal the lowers seem to help the numbers and stability the further out they are. I’ve always mounted them for clearance. Same with the upper. Towards the center seems to balance it better so I do my best to get the axle mount towards the middle, clearance pending. the track bar takes most of the side loading stress from steering and general force.

 

[06h3]

Yeah I was asking about frame side vertical separation.

I haven’t burned anything in. Contemplating between 9.25in of separation and 7* of lower control arm angle or 10.25in separation and 9* of lower link angle....figured I’d sleep on it.

Upper link is basically flat at 2* of angle....which is better then before. I made the upper longer

 

[Lincoln]

If I remember correctly, in general, upper link as flat as possible and I looked at the separation in the calc. Less parallel and different lengths affects the pinion rotation. In a perfect world, with a cv shaft, the pinion would stay pointed at the tease output throughout the travel. But that causes caster change. In what I built I tried to find a midpoint were the driveline angle wasn’t a bunch and neither was the caster change. I did that by getting the angles I wanted in the calculator, then varying the lengths.

As an example. On the rear 4 link of my dads rig I was dealing with an 18” long rear drive shaft. I made the pinion rotate up when dropping. So at ride height it was the normal 1 degree down, At full drop it’s 2 degrees up. I was able to keep from having joint bind by doing that. By keeping the desired angles the same and cha the upper length the calculator output change was minimal.

 

[06h3]

Back from KOH! I will get an update here soon. The new 3 link Performed flawlessly and so did the ARB air locker.

I left my bent tie rod on and came back with an even more bent tie rod so I’ll have to address that soon

 

[06h3]

Great to meet you on clawhammer and thanks for the sticker! Bmxbry9

KOH was good, it is getting more and more crowded to the point where I ask myself if it’s worth going to KOH at all. Maybe I go the week after? I showed up Thursday AM....maybe next time I should up Friday AM and stay later in the week.

Anyways, I figure I will mention the changes. I ended up with 10.25in of separation, lots of bracing and Support to the upper and lower mounts on both the frame and axle side.

1st pic is the gussets to the lower frame side links. I also wanted these because I had an instance where I backed up and got caught on the back side of the link mount, now it’s ramped to fix that issue and adds strength.

2nd pic is track bar gusseting. I tried to gusset everything. I never had track bar bracket issues but figured I’d just add them for good measure.

The 3rd pic is tube that links in from the back of the 3rd link bracket and ties into the frame.

4th pic is the 3rd link axle side upper. It’s been cut and raised for more height, boxed in, plated in spots to be 1/2in thick, and has baby trusses welded to them.

This weight is a full tank of fuel, without me in it, pretty much empty. Full doors...no spare. Doors weigh in at 330 Lbs. So ditching them is quite a bit of savings.

 

[06h3]

I also installed an ARB. I first tore it apart to make sure it had the new bonded seal. Not the old style that is prone to leaking.

checking for clearances.

So now for KOH.

Hummer performed flawlessly!! I ran Jack, blueberry, chocolate a couple times, and clawhammer. I also did recovery at backdoor for the EMC race. I wish we got to run more but we had fun anyways.

I don’t have a pic of it but I made “trapdoor” on blueberry. 2-3 years ago I had my closest rollover on it. I have seen plenty of denied attempts and rollovers on trapdoor on social media during koh so I am stoked to have made it!

On chocolate thunder...

my buddy sheered his knuckle studs, we pulled the tires and springs and put it on the back of the hummer via shackles. We got from the end of jacks back past the mailbox and to the rocky section before the sand hill. Left it there and went to town to get parts and fixed it the next morning.

My rear leafs had a work out!!

Backdoor recovery.

Overall it was a successful shakedown. Jackhammer was the most challenging trail we ran and I didn’t pull cable. I made the first part of the plaque with ease. 2nd part I made but had to stack a couple rocks, I took a bad line, after watching everyone after me I realized the line I should have taken...but ARB and 3 link did their job and I’m ready for the next run!

 

[Bmxbry9]

Sick running into you too! I feel the same, we were down from Thursday to Wednesday. Next year I might go Friday to Friday to avoid the crowds