TJ rear end "torque rise" issues

[MemorEsto]

Now that the TJ is pretty much a dedicated trail rig, I've given up on trying to keep it street legal(ish).

I've had a Detroit locker in the rear for about 4 years and have gotten used to it's characteristics. I'm just looking for some suggestions for improvement.

Currently I have RockKrawler 4 link short arm uppers and lowers... planning on stretching rear 5" at the least with Clayton 4 link.

Everyone with a detroit in a TJ with a 5 speed knows when you let off the clutch the driver side lifts up from torque.
This is becoming an issue on hill climbs now that I trailer and am doing harder trails I wouldn't have done with driving the Jeep there.

So, will stretching improve the rear end lifting issues? Would a spool be more stable? I have 4" Currie HD springs and they aren't that old.

[justin'sbig7]

I hated my Detroit HATED it. I went to ARB in my dedicated trail rig and for tight turns and other maneuvers it is really nice to unlock it.

[Deadman 94 xj]

I think the stretch would help a lot. The detroit in the XJ didn't lift like shorter wb rigs do.

[oros35]

Stretch helps, but the key is the location of the links. The ratio of seperation of the links at each end needs to be in the right range. Search "anti-squat" or 'suspension squat'. That along with several other factors cause, or keep from happening, what you describe.

[dan58]

Stretch helps, but the key is the location of the links. The ratio of seperation of the links at each end needs to be in the right range. Search "anti-squat" or 'suspension squat'. That along with several other factors cause, or keep from happening, what you describe.

This. And ditch the Detroit. It's not just manuals that have those characteristics. The Clayton stretch kit will certainly help, and you can't mess up the geometry. Do you have a rear sway bar?

[MemorEsto]

No rear sway bar, besides selectable what option is there ?

[SirFuego]

I've experienced that issue on a friend's TJ. And to a lesser extent, I've seen similar issues (and complaints on forums) about that same issue even on lifted ZJs (105-106"ish wheelbase). However, the problem always disappeared when they switched to long arms.

My layman's theory without talking about anti-squat, etc. is that the rear end torque gets transmitted through the control arms to the chassis. With short arms, they are much more vertical so that force pushes "up" on the chassis. Long arms are much flatter so it pushes more horizontally -- thus the chassis doesn't move (as much). I'm sure you can mess up a long arm setup to give you poor characteristics as well, but I'm talking off the shelf long arms...

[MemorEsto]

The plan is to use stock mounting location at frame for control arms, use a 26" mid arm and push axle back 5-6". I'll have to use some blue tape or PVC to mock up the angles.

[dan58]

Why not use Clayton's stretch kit? Can't be much more than what you're thinking???

I think we often forget what it's like to drive a stock TJ. Mine exhibited some of these characteristics even when bone stock (and an auto). When I had a Detroit, it was worse. The Clayton kit helped it tremendously.

[MemorEsto]

Clayton is making the arms for me. Just cut to 26".

[dan58]

Doing the double triangulated? Seems like a good time to do that. And it'll avoid rear steer. Be sure to request plug welded inserts.

[MemorEsto]

I wasn't planning on double triangulation.. This is what I'm planning on.

[13below0]

Why are you not making the arms yourself? Especially if your using stock mounting locations. 2x2 is fairly inexpensive and we have square tube end adapters in stock. Even you farmers from Corry can figure this out Lol.

[MemorEsto]

Clayton's is about the same price as buying all the materials and doing it myself

[2002wranglerX]

Clayton's is about the same price as buying all the materials and doing it myself

I've run into the same thing. Jeremy from RK was building me custom length arms with flexjoints on both ends cheaper than I could build them.

[oros35]

I did mine double triangulated, best thing I've done for rear suspension. Didn't think I'd notice it as much as I do.