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GMFS Uber-Member
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Discussion Starter · #1 ·
All right, I know a lot of guys have done solid axle stuff and a few guys have all the info in their head and don't like to just blab, so I'm trying to get my ideas all together before I just ask for trained secrets.
I want to do a solid axle swap on my 2500HD. I'm thinking coilovers because that's what I'm thinking. I'm not against leaf springs, but for this project, coilovers are the way I want to go. If I'm using Sway-a-Ways, is it worth the extra $150 or so per corner to step up to the 3" shock or would the 2.5" work just fine. It'll be supporting a Duramax/Allison combo. I know the 3" has a 1" shaft, and the 2.5" has a 7/8" shaft, is the 2.5" strong enough?
I'm looking to do a 4 link setup, front and rear. I've read other places about how a triangulated 4 link in front is bad with steering, or something like that. Can anyone explain? I'm thinking of doing something similar to HRC's white GMC, just not as high.
The truck is going to be half street, half trail duty, so I can't have stuff falling off or needing constant attention. So I'm thinking of using Rubicon's Super Flex joints at one end of each link, and a normal bushing at the other. I've heard this is better than a heim, even if not as strong.
I guess that's all I can think to ask for now. Correct me anywhere I'm wrong, or explain why something isn't what I think it is, if you can.

Thanks
Chris
 

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NCOR
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Triangulated 4 links move the axle up and down perfectly centered, this is problem with mechanical steering as the drag-link moves in an arc. So you will get bumpsteer with a triangulated 4-link up front unless you use hydraulic steering.

2.5"'s will be fine, you can use 3.0"s if you want or if you intend try and use it at speed in over rough terrain. The extra fluid and body size will shed heat better than the 2.5"s. Most of the guys with these huge c/o's are just making a penis statement though. The shaft will be fine, as long as you're only loading it in compression and tension and not in shear the diameter should not ever become a problem.

The standard 2.5" 9/16 rubicon flex joints will wear out and the bolt size just isn't large enough to hold the torque and resistance from weight your truck will have. Just ask Jason, and his Vortec 4.7 is only rated at 290hp and 440tq stock or thereabouts. Heims are a good option, provided you get quality units and large ones. None of this 3/4 x 3/4 QA1 crap. FK's or bust, 3/4 x 7/8 is a starting point but the 1 x 1's and the 1 x 1-1/4's just have so much more bearing surface area which will increase joint lifespan. Personally Id ditch the bushing idea as well under your rig, articulation and prodigeous torque is just going to wipe them out regularly.

These are also pretty neat: http://pirate4x4.com/forum/showthread.php?t=588300
I ordered 3 of them last week, but I won't be testing them any time soon. Should be a neat comprimise between large heim and johnny joints. You get the same 3/4" through bolt you would with a 1 x 1-1/4 heim with HMS's, and almost the same misalignment. Then you also get the larger threaded shank, larger races for increased life and the races are solid! We'll see how they pan out though.

All that said a 50/50 mix is pretty high, are you building a toy you only drive to go wheel?
 

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Discussion Starter · #3 ·
Kyle,
Thanks for the input. I've read a bunch of your threads about your build (I think) and from what I've seen, you know your stuff, so your input is appreciated.
The rig is gonna be more than likely just something to get out to the dirt, not a daily kind of thing, but it will definitely see road and highway use, so it's gotta hold up. I like the idea of heims, but I guess I was mistaken thinking they were too harsh for road use, maybe it's just the smaller ones.
Thanks again. I'll keep everyone posted when I actually start this in a couple months.
One last thing, does anyone have a good link calculator? I've been looking and found one, but my computer savvy-ness is lacking I guess and can't understand it. It's Greg Blanchette's ExcelCAD v2.1a if that helps.

Thanks again
Chris
 

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I wouldnt personally go with the Rubicon Express joints either....I had them on my truck but I should have just ran a heim, especially if I had a Duramax.... I never did have any problems with my joints and I had over 20k miles on the lift but it was strictly street miles..
 

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I run a 3 link (single upper link) with panhard in the front of my 95 GMC 1500 with 2.5" coilovers. I currently run 1" heims reduced to 5/8" bolts and teraflex 9/16" joints but am going to switch to 3/4" bolts all around for security. Because of the size of your truck and the intended use I'd recommend joints with at least a 5/8" bolt. You will most likely need swaybars, I run a 1" solid with 16" arms and it is not enough. Without one it is nearly undrivable at speed, though different configurations will give you different results. Are you designing and fabricating this yourself?

I built my own link calculator if you would like to try it. I didn't put any graphics, but to me it is more user freindly in entering the link mounting locations than the one that is currently around. People seem to rely on these calculators too much when in reality they are not very helpful. The best way to configure a setup is to sit and look under your truck and picture where the links could possibly mount, how brackets will mount and how easy they will be to fabricate, Where links will possibly interfere, etc...Then use the link calculator too see where you are at.
 
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