Build Hummer H3 Build

Most diesel transfer tanks are still steel. It won't rust as long as you keep gas in it and keep using it. It's when they sit that they rust. Usually either the top section exposed to air and moisture or if water got in the fuel, the very bottom.

Building a sealed tank is not as easy as ome would think. Even a good weld can easily leak. The main trick is to bevel about 1" and over lap welds when starting and stopping. It's not always pretty, but much better at making a sealed weld.


Does watching Dave's V10 superduty give you more confidence in a rear 3 link?
 
YotaAtieToo said:
Most diesel transfer tanks are still steel. It won't rust as long as you keep gas in it and keep using it. It's when they sit that they rust. Usually either the top section exposed to air and moisture or if water got in the fuel, the very bottom.

Building a sealed tank is not as easy as ome would think. Even a good weld can easily leak. The main trick is to bevel about 1" and over lap welds when starting and stopping. It's not always pretty, but much better at making a sealed weld.


Does watching Dave's V10 superduty give you more confidence in a rear 3 link?
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Yeah, doing the 1in overlap would be required for sure.

It has, at this point we are making a game time decision. I know what it takes for each one but having another set of eyes on it will help make the decision. I have brackets for both a 3 link and 4 link, I’ll get a set game plan when my buddy shows up but seeing Dave’s 3 link gives me hope. That’s a big heavy truck and I watched bleepin Jeeps 2023 UA video. In every shot I saw Dave he was flogging it pretty hard. Not as hard as that damn Quigley van :lmao: but pretty damn hard! UA2023 looked like a tough year on rigs

 
YotaAtieToo said:
The main trick is to bevel about 1" and over lap welds when starting and stopping. It's not always pretty, but much better at making a sealed weld.
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The trick is to just build that **** out of 1/8 and accept the resultant weight penalty instead of copying all the youtube ****s who build everything out of bead rolled sheet metal and TIG weld everything (because fabrication showboating like that is what know-nothings want to watch).

It's way easier to get something thick to seal because your pool of molten metal and the area of base metal you're liquefying is just that much bigger.
 
IMG_8810.jpeg


It’s been a month since I’ve been in the garage (or there abouts)

Got a few hours in yesterday. Cut the rest of the crap off the Eaton housing, got it all down to bare metal, cut the air bump mounts off the frame, stripped the paint off the frame more. I’ll be local to home this week so I’ll cut the 2 front spring hanger mounts off, assemble the new Eaton from the old Eaton. drop the tank, drain it, so it’s easier to get it in and out during the build while we determine 3 or 4 link.

All major parts are in, just need some little crap like extra 5/8 drill bits and stuff.

2 weekends till it’s go time!!
 
What is the benefit of the eaton rear end over a 14 bolt? Other than clearance/weight?
 
Mattygwheeler said:
What is the benefit of the eaton rear end over a 14 bolt? Other than clearance/weight?
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I think those 2 reasons alone are enough of a benefit, but another is a load bolt. 3rd pinion bearing support prevents pinion deflection on a 14 bolt. The eaton has the 3rd pinion bearing support and a load bolt to prevent ring gear deflection.

I am also a sucker for cool/different axles. So an Eaton is cool and different compared to the regular 14 bolt.
Same for my front axle, dana 70 with side adjusters like a 14 bolt.
 
06h3 said:
I think those 2 reasons alone are enough of a benefit, but another is a load bolt. 3rd pinion bearing support prevents pinion deflection on a 14 bolt. The eaton has the 3rd pinion bearing support and a load bolt to prevent ring gear deflection.

I am also a sucker for cool/different axles. So an Eaton is cool and different compared to the regular 14 bolt.
Same for my front axle, dana 70 with side adjusters like a 14 bolt.
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What trucks did the eatons come out of? Most were 8x6.5 i assume?
 
Mattygwheeler said:
What trucks did the eatons come out of? Most were 8x6.5 i assume?
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All were 8x6.5, WMS was 63-65in WMS. Some rarer ones were like 69 or something. They came in 1947-1972 Chevy C20-C30s

Eaton HO72 Tech Thread

The old site had a ton of tech and info on the HO72. I will just give a short recap on the axle. -Axles were used from 1947 to 1972. -The difference between the HO72 and HO52 is the factory load bolt. -Axle shafts are 1.5in coarse 17 spline. Many argue whether if they are stronger or weaker...
irate4x4.com irate4x4.com
 
06h3 said:
I think those 2 reasons alone are enough of a benefit, but another is a load bolt. 3rd pinion bearing support prevents pinion deflection on a 14 bolt. The eaton has the 3rd pinion bearing support and a load bolt to prevent ring gear deflection.

I am also a sucker for cool/different axles. So an Eaton is cool and different compared to the regular 14 bolt.
Same for my front axle, dana 70 with side adjusters like a 14 bolt.
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I remember when you first started diving into it on the old place, can you do a quick recap?

I remember something about a really small spline count but they were massive splines, are you still running those?

Also, how has the load bolt worked out? Never seen one in application but in theory I get it, but once it “works” the first time by preventing deflection won’t the bolt be instantly worn down and have a higher tolerance and therefore prevent less and less deflection as time goes on?
 
fl0w3n said:
I remember when you first started diving into it on the old place, can you do a quick recap?

I remember something about a really small spline count but they were massive splines, are you still running those?

Also, how has the load bolt worked out? Never seen one in application but in theory I get it, but once it “works” the first time by preventing deflection won’t the bolt be instantly worn down and have a higher tolerance and therefore prevent less and less deflection as time goes on?
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Diving into what? The eatons?

The shafts are 17 spline but the OD is still 1.5 like a 14 bolt. I ran them for about 5 years. I broke 3-4 shafts over that time. I can say with confidence that the Eaton Detroit locker is substantially stronger than a 14 bolt Detroit. I have never seen a Detroit last 3-4 broken shafts in any axle (14b, ford 8.8, d44 I have all seen get wiped out if a shaft broke)

I have switched over to 14 bolt shafts in the Eaton about a year ago which I was breaking about 1 Eaton shaft a year but this past year has been way more wrenching and less wheeling so time will tell.

As for the load bolt, in theory, yes it would wear down. I imagine if if it touches the load bolt for a split second during high load the wear is minimal. I have checked the load bolt before and it wasn’t noticeably further from the ring gear. I know racers use them and I can imagine the load they see they have to probably check them after each race
 
06h3 said:
Diving into what? The eatons?
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Yeah, I think I remember your thread on the old place and when you first were starting to get the HO72 figured out. But maybe I’m making that up because it’s been forever lol
06h3 said:
The shafts are 17 spline but the OD is still 1.5 like a 14 bolt. I ran them for about 5 years. I broke 3-4 shafts over that time. I can say with confidence that the Eaton Detroit locker is substantially stronger than a 14 bolt Detroit. I have never seen a Detroit last 3-4 broken shafts in any axle (14b, ford 8.8, d44 I have all seen get wiped out if a shaft broke)

I have switched over to 14 bolt shafts in the Eaton about a year ago which I was breaking about 1 Eaton shaft a year but this past year has been way more wrenching and less wheeling so time will tell.
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So you’re running 14b shafts with the HO72 carrier and side gears swapped out? That’s what I was asking for a quick recap on the HO72 as built currently. I can go back and read though if it’s too much lol
06h3 said:
As for the load bolt, in theory, yes it would wear down. I imagine if if it touches the load bolt for a split second during high load the wear is minimal. I have checked the load bolt before and it wasn’t noticeably further from the ring gear. I know racers use them and I can imagine the load they see they have to probably check them after each race
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Makes sense. Run it if you got it (I.E. HO72 stock), but for casual wheeling I’m not sure the theory makes sense to me to go through setting one up like the Jantz kit does. Racing, as a consumable yes that makes sense.
 

Eaton HO72 Tech Thread

Sometimes the numbers are stamped on top of the third, on top of the pinion oiling slinger galley, the bump on top of the third. I've seen them there, but not always. So I went and looked at the remnants of a 1954 chevy 3600 delivery truck today. There were numbers on top of the pinion oiling...
irate4x4.com irate4x4.com

Mother ****er….maybe I spoke too highly of them lol time to make some decisions

Post #320
 
06h3 said:

Eaton HO72 Tech Thread

Sometimes the numbers are stamped on top of the third, on top of the pinion oiling slinger galley, the bump on top of the third. I've seen them there, but not always. So I went and looked at the remnants of a 1954 chevy 3600 delivery truck today. There were numbers on top of the pinion oiling...
irate4x4.com irate4x4.com

Mother ****er….maybe I spoke too highly of them lol time to make some decisions

Post #320
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7 years and that resume? Throw another R&P together (I think you said you had one) and drop it in.

Figure out the Dana 80 or whatever in 2030

When was the last time you put eyes on the ring gear, meaning could it have broke a while ago? Clearly you somehow got lucky the chunks didn’t get chewed up. So what if you’ve been running it like that for years :eek:
 
So you don’t have to head to the Eaton thread (unless you want more detail) the final verdict was a failing carrier bearing caused the R&P to fail on 2 teeth. This also lines up since I ran the Eaton successfully on a carrier with fresh carrier bearings for years. Last year, I put together my 14 bolt locker setup in a different carrier I had laying around. That had original 1950s carrier bearings with who know how many miles. The thrust side had a ton of play in it, especially compared to the other bearing. This allowed things to move around and make a bad pattern. Anyways, the plan is new carrier bearings and slap another 5.14 R&P I have in and give it hell.

I’m sitting in the Vegas airport leaving sema. Buddy flys in Friday. I’ll get the garage prepped tomorrow night. Move the F550 out of the garage. Line up the welder, plasma cutter and all fab tools and get this thing going this weekend! I’m excited and nervous at the same time
 
Alright, night 1 is done. We will proceed with a 3 link unless something drastically changes tomorrow during our work.

New bumper is done. It’s very simple but looks badass imo, my old one sat out far to cradle the spare. Now I don’t run a spare. If I do, I’ll make a hitch stinger of some sort.

IMG_8924.png

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We still have to tie in the tubes and weld one more spot but super stoked on it.

IMG_8925.png


Simple design. Cut 2 mounting points that go the frame rail slot

IMG_8927.png


IMG_8926.png

Start of the 3 link, we cut up a barnes truss that wouldn’t work. Gussets will be added but on track for 11-12in of separation.
 
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Day 2 is coming to a close. Plenty to still do but links are set. Locations are set.

Track bar is very strategically placed. Yes, it’s on the driver side which seems counterintuitive. Jeep does the opposite. I have seen a Tacoma kit that has the same 3 link f/r track bar both on the driver side, martec engineering and he rally’s that damn thing. The problem I have is track bar placement is limited. On top of the axle, I run into the pumpkin and 3rd link bracket. In front of the axle I hit the coilovers. So behind the axle it goes, even then it has its own issues, but less of them. I put the track bar below the upper 3rd link and above the driveshaft so it’s barely snakes through.

IMG_8930.jpeg


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The track bar still needs gusseting and double sheer.

IMG_8937.jpeg


Lower link angle at ride height will be about 7 degrees which is ideal.

Shock mounts are low. I’ll talk more on that later.

IMG_8938.jpeg



Upper shock mount. The front one ties into the other side, the rearward one doesn’t but I believe the load is transferred. Correct me if I’m wrong.

IMG_8943.jpeg


We may have been able to notch a few things and get it ever so slightly higher but it’s a ton of difficult non clean sheet metal work.


The frame side upper is up HIGH! Which is needed for anti squat

IMG_8931.jpeg


On the 2nd hole it’s above the framerail.

Preliminary #s are anti squat at 78% and roll axis at 5*

The pros are, the suspension will behave a ton better compared to leafs (in my opinion and I hope it’s true) it will do what it’s asked immediately vs anti wrapping itself to death.

More up travel. Going from 3.75 to just over 5
More down travel going from about 5 to 6-7.

The only thing I worry about is the lower axle side coilover mount. Leafs had clean axle tubes and nothing hung low. These hang low, but it was my choice, I didn’t want to go through the cab and we looked at it 1000 different ways, no way to do a trailing arm to help packaging, no way we could angle them any farther back, the only option was going from 12s to 10s or hang them down.
 

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GGRR 4555 said:
Looks Epic. Hope it holds up against those Hillbilly tires! ;)
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Those tires will get me up winch hill 0.5 while you watch from the bottom :flipoff2:
GGRR 4555 said:
You should get a photo from down low so you can see the shock mounts and resi's.
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I will do that. good point, thanks again for all the help this weekend.
 
'84 Bronco II I hope you dont mind me quoting your post from "hows my numbers" thread in here so people can reference it years later. I will copy my response back in the next post. I write a lot, I get made fun for it, but between your post being qouted and my response, I exceeded the max characters for a post :lmao:


'84 Bronco II said:
I didn't say anything when I read your build thread because it looked like you had everything finalized, buuut since you're asking here...

I understand that you have a lot of packaging contraints, but you rear anti-squat is too high, mostly because of the angle on your lower links; that's why you had to get so much separation at the frame to get back to a reasonablish anti-squat number. As Treefrog mentioned, for a crawler, under 50% antisquat is a good place to be, but that number is going to depend a ton on your CG height input.

I realize your Hummer is tall, but I think your 45" COG estimate is way too high which is lowering the Anti squat values the calculator is outputting (EDIT: My "way too high" statement was based on you mentioning 79% in your thread, obviously your calculator numbers posted here are way lower because of your frame side separation and your unrealistically high COG input). In reality, your antisquat numbers are probably much higher. What your steep lower link angles and high anti-squat are going to do is cause the rear end to jack and hop on steep climbs whereas a lower anti-squat will stay planted and put down traction. It will also ride a lot harsher than flatter links with lower anti-squat values.

I know you are concerned about separation and the forces the links are putting on the mounts, but I would raise the axle-side lower link mount to at least the axle centerline. This will help flatten the lower link, improve your flex steer, lower your antisquat, and give you more ground clearance. This still probably wont be enough though and I would make your lowers a bit longer. It looks like you could extend the lowers and inboard them to the crossmember just ahead of where you have them mounted on the frame now. In addition to getting them flatter from the additional length, inboarding the lower frame mounts will improve clearance and help reduce flex steer. Your ~10° lower link angle sucks, try to get it as close to zero as you can without making your frame side lower mounts rock anchors. I mentioned flex steer a few times because your current design has a lot, giving it a tendancy towards oversteer which can feel squirrely.

Obviously changes you make to your lowers are going to affect what you need to do with your upper link to maintain a good pinion angle through travel and get your anti squat where you want it. If you know someone with corner scales that can handle the weight of your rig, getting an accurate COG height will help you out a lot, otherwise keep a good bit of adjustability in your upper mounts. I understand your upper is probably where it is due to space constraints, but there is no need for any triangulation in the upper and the closer you can get the frame and axle mounts to the center of the vehicle, the better to avoid asymmetric forces on the chassis which can cause suspension performance quirks.

Your rear panhard is another big issue. The angle is very steep which is going to transmit more force into the chassis (suspension harshness) and result in a lot of lateral axle movement which can cause clearance/binding issues for driveshafts, shocks, and tires. The lateral movement can also make it feel unsettled at speed with large suspension movements. You have your ride height modeled at mid travel which means you want your tack bar flat at ride height. You need to raise the axle side mount, lower the frame mount, or a combination of the two. The easiest move looking at your setup at this point would be to lower the frame side mount, but that will lower you roll center; however, a sway bar can easily fix that issue. You would have to relocate your bumps and/or upper link mount, but if you could get the track bar on the back side of the axle so that you are not trying to go under your upper link, you could potentially raise your axle-side mount quite a bit and extend the track bar as close to the passenger rear wheel as you can which will also help the static angle as well as the angle change/lateral shift through travel.

One last thought not related to the calculator, but still related to your new rear suspension setup, is there any way you could get your coilovers outboard on the frame? This has a few advantages: you could tuck them up in your wheel well so the don't have to hang down so low (presuming your tires will clear), the lower mount could get a lot closer to the wheel which helps clearance if you do have to hang them below the axle, and lastly it will improve stability and reduce body roll and torque twist significantly over your inboarded setup.
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06h3 said:
It was quiet over there, so I figured some were biting their tongue, but I have thick skin. I can take a flaming about how I am a ****ing idiot who can't build suspensions, but at the same time, give the reason so when someone else reads my build thread in 10 years from now, they can learn. I spent too much time reading 15 year old threads wading through "OP doesnt know ****" to find the 2-3 solid answers on WHY OP doesn't know ****.

I will go comment by comment but first start off by saying that I appreciate the input, am willing to make changes (at this point after I drive it) and am committed to this rig so I will make the changes as I see fit. I have redone my 3 link front a couple times, gone through numerous coil spring, shocks/shock tuning and ultimately to coilovers, axle swaps, changing link locations etc. so I just want people to know the advice won't fall on deaf ears and is a waste of time as people type stuff out to give me advice. With all that said, any changes won't be immediate since it is brand new. I will also say, building a link suspension in a weekend has its pros and cons, pros: its done fast! Cons: hindsight is 20/20 so I may see things differently after. I had a friend fly out, we worked our asses off and accomplished a lot but in order to do that we couldn't ponder much. So anyways, thank you for the solid input, I do truly appreciate it.

Ok, on to business.

Lower link angle. In reality I could have gone further back and use a shorter link bracket, but link angle is 7* at ride height, I thought it wasn't terrible. Jake Burkey on busted knuckle rock rods tech videos says keep it under 10*. I thought that was under 10* at ride height, maybe he meant at its steepest angle? Either way, it is something I can change in the future if it is problematic. I can say that I CANT inboard my links unless I ditch the factory tank and if I ditch the factory tank then I will go with a 4 link. While all the pics were on the pass side, the factory tank is on the driver side and is right up against the frame rail so inboarding is a no go, and trust me, if I could, I would have, I saw benefits to inboarding my lower links up front when I did that. I wish I could.

I will touch base on a few topics here. Anti squat, upper link placement, and COG. One of the few things I had going for me in this build is that the H3 has a metric **** ton of room for frame side upper link placement. I could place (2) 4 hole brackets on top of each other and still have room to cut up a 3rd one and have a total of 10 holes so the adjustability is basically infinite in my opinion. I threw in my COG all the way down to 30 for reference (which I highly doubt it is) and I can still get it under 100% with my current layout. I would be willing to put in the work to find my true COG. Heres some info on COG, think thats the correct formula?



COG calc.jpeg IMG_8986.PNG

So, I am not concerned on Anti Squat, I am very confident I can get it right, I just need to know what my true COG is so I can accurately place the link on the frame side. As for axle side upper link placement it wasnt really for anti-squat, it was a priority that I am placing this upper link bracket as high as I can to reduce load off the upper link, I would figure out anti squat later and it just so happens that going up that much helped my anti squat.

As for track bar, yeah. I agree 100%, of course I wish it was flatter. I would have to go back and look; I can't remember if I could put it over the upper link. I may have room for it. I was stoked that I was having a 41in long track bar, I asked a few others with 3 link rears and it was longer than anyone else, but I guess it doesn't matter because it sits at 13* angle at ride height. I vividly remember having it longer then it was and it ran into the upper link because they travelled at different planes. The quick answer was shorten it a few inches, if we had more time, maybe we would have chosen other options. Anyways, I can't lower my frame side in its current position because it would hit the 3rd member at full bump. I could potentially bring my axle side over the upper link. The reason I didnt go behind the axle is because the coilovers were there. I see that 4WU puts their track bar behind the axle and the coilovers behind the axle. From pics it looks like to do that they put GIANT coilover mounts to space the coilovers far off the axle tube. I didn't want that kind of leverage on something that holds my vehicle up, especially because I weigh quite a bit more than a toyota. So thats why the track bar went behind the axle. Admittedly I am nervous about rock crawling performance with the coilovers and links in big boulder canyons. In the canyons my leafs were sprung over, the mount was short and tucked up way higher on the frame side then the links, I had nothing below the axle tubes. Leafs worked awesome there but then on ledges, even with an anti wrap bar, I felt the power wouldnt hit the ground immediately, the springs wanted to wrap in certain situations and loads. So this brings me to the next topic of outboarding. I was concerned that outboarding would cause clearance issues. My framerail is very wide. Off of memory it is 43in wide. My axle WMS (with spacers) is 69in wide. It is something I will consider though. I felt like we just wrote it off because of how wide my axle is. Id be curious if my coilovers are mounted wider then a TJ just because my frame is that much wider compared to a TJ with outboarded coilovers. Probably not apples to apples but I would be curious. They are angled back and inboard compared to the axle so I hope the inboard frame side does provide some stability because of the direction they are going.

Readers digest version: Maybe I could put the axle side track bar up above the upper link, or get it back behind the axle and live with giant pain in the ass hanging 12in behind the axle tube coilover mounts or go behind the axle, put coilovers outboard and in the cab and on top of the axle tube but dont really wanna go in the cab.

One last question, my COG to roll center, I want predictability and stability, is there a percentage between the two for that? It seems the higher the roll center, the more stable it is but the less predictable it is?

I think I covered it all. I really do appreciate all the insight and would be interested in any other opinions from others or comments from you on this.
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Here is my response in the other thread, and the pictures GGRR 4555 asked for. I do think the lower link mounts transitions nicely to the coilover mount and here are the machine gun mounted resi's

lower link h3.JPEG
coilover mount.JPEG
 
I would agree with everything thats been said. I don't know where 79% AS being too high came from though? I've always thought 60-80% for a streetable rig is where you want it, and I've been stretching that out to 85%. For a buggy, sure go to like 50%.

Your rear track bar is going to suck at speeds. I'm talking, driving on the highway over things like bridge transitions. You will feel it. Its counter intuitive, but from experience I'd drop the frame side down and get it level. It will drop the roll center, but raising the axle side has other negative issues. Roll center height is what it is with link suspensions. I would focus more on roll axis angle and over/understeer. 5* oversteer isn't a lot, but it could be lower by just raising the lowers on the axle tube. I get there are other issues with that. I think drive it how you have it, then you'll want to fix the rear track bar and try again. It might be fine at that point.

Just my .02.
 
Ghetto Fab. said:
Your rear track bar is going to suck at speeds. I'm talking, driving on the highway over things like bridge transitions. You will feel it. Its counter intuitive, but from experience I'd drop the frame side down and get it level. It will drop the roll center, but raising the axle side has other negative issues.
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What's the big tradeoff? Seems like he could at least raise it up a little and if that doesn't do it then start dropping the frame side.
 
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