H3 4" lift kit

[DustybirdmaN]

So this is a H3 Rancho 4" knuckle. Notice the short steering arm.....


Here's the BDS knuckle. Wayy longer steering arm. I believe this is my issue. Luckily, tons of meat to grind on and re-drill inwards towards the hub center. I'll get this beat yet

 

[amrg]

If its shorter why not use the H3 outers?

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[DustybirdmaN]

It's not a matter of toe in/toe out. By longer steering arm, I mean the measurement from center of hub to tie rod mount. The H3 knuckles are an inch shorter. I'm pretty sure this is throwing the geometry out. The knuckles turning radius is set for wheelbase and whatnot, to an extent.

 

[DustybirdmaN]

I talked to my alignment guy, he concurs. I measured the H3 knuckle, its 5.5" from center of hub to tie rod mount. The BDS knuckle is 6.5". This is apparently very significant. Changes the steering leverage, speed, and radius. We're both fairly certain that if I modify these knuckles to be the proper length, I'll be in business. It shouldn't be too difficult.....theres lots of room, and I have a good set of drill bits, and the 7.5° reamer. Plus this is my daily driver rig, so necessity applies as well haha. I may even be able to getter done, still bolted in the truck. We shall see

 

[DustybirdmaN]

Finally got around to doing surgery. Went well. Ended up having to use Canyon inner tie rods, with H3 outers. I still need to go get another wheel alignment, but I dialed it in as close as I could. After test drive it feels much better. I'll get the alignment soon, put some real miles on and report my findings

 

[SlcHummer]

There was a build really long time ago that did exactly what you just said. Samco fabrications did that, 14" of travel I believe. They had to move the battery and coolant reservoirs to do that. Too bad you cant search the threads anymore (they were on www.hummerxclub.com)
I hope someone here still remembers it, or has better info than me. Sad when a forum dies lots of info goes away...

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It may be possible to find it using https://archive.org/web/ however I expect searching the forum will be difficult without being able to login

 

[DustybirdmaN]

Little update: I changed out my leaf spring bushings and frame bushings (they were absolutely shot, causing alot of ass end sway haha), added air bags in the rear, and installed the front sway bar (cut the stock end links in half and welded in some 1/2" pipe to extend them to 8 1/2"). It still has a bit of bump steer....but after doing some more research on what causes bump steer, and going over the H3 Rancho 4" lift installation instructions (the pictures offered alot of insight), I think I know why its happening. My tie rod angle is too flat in comparison to my a-arms. I should have tapered the tie rod mounts from the bottom-up. Sooooo, I'm ordering another set of knuckles, re-drilling them, and tapering them bottom-up. It's not even that bad right now, but I'm picky. I've gone too far to give up now.

Is there someone out there with the Rancho 4" lift that I could get some measurements from? I've been going off of pictures of the Rancho knuckles and comparing to stock knuckles to get a half-assed idea of where I should be, but actual measurements would be awesome to help clarify. Please spread the word, a few easy measurements would be GREATLY appreciated!

I would actually love to get my hands on a set, just to draw something up with correct measurements, or better yet build a jig. I could build these relatively easy

 

[amrg]

I recall a few ppl found incomplete lift kits, 1 side knuckle and where posting here and on fb looking for another side. If those guys still own their H3s, id bet they still have the knuckle available since rancho doesnt supply replacement parts anymore. Just need to search abit

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[DustybirdmaN]

Thanks to some help from Alpha X, I got some proper measurements of a Rancho knuckle to work with. After measuring my BDS knuckle, I found that it is exact measurement from top of lower ball joint mount, to top of upper ball joint mount. After moving my tie rod inwards toward the hub center, it is bang on as well. But....vertically, my tie rod mount is 3" up from where it should be. If I plug weld, then re-drill/taper it from bottom-up, I'll be roughly 3/16" too low. So right now I have crazy bump-in steer. After I flip the tie rod, I'll have a slight touch of bump-out, and that's far more desirable than any amount of bump-in. I'll get this flipped and report back

 

[amrg]

3/16 is nothing. The tie rod should be parallel to the LCA and I guess you are damn close to that!

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[DustybirdmaN]

I finally bit the bullet and just tapered the tie rod mounts from the bottom-up. It actually worked out really well, they're plenty solid. I ended up trimming off the extra bit of steering arm on the knuckle for clearance for the outer tie rod when at full lock. Like I suspected, it now has just a touch of bump-out, but I couldn't actually notice it while driving. It feels great. But....at full droop, the tie rods are stressed out....I would need to re-drill the tie rod mount at an angle to fix this. For now, it's all good. But I do plan on buying new knuckles and doing it all over, with the mount hole at an angle. I do still need to limiter strap it if I want to wheel it hard without busting cv axles, so maybe I'll do that first, then see if my tie rods are ok at that limit.

 

[little diesel]

Any updates or pictures

 

[LShummer]

Any updates or pictures

 

[LShummer]

Thanks for this write up, lots of good info! I’m gathering intel for my H3.