[tpreston]

I have a 05 LJ Rubicon. It has had a handling issue since I bought it 2 years ago.
The rear end will "get loose" whenever it is on a slippery surface - rain or snow. It also does it when I hit a bump in the road. Hard to describe but it feels like the rear wants to spin around.
It has 49,000 miles on it. I thought the problem was in the front suspension. I rebuilt the entire front - upper and lower ball joints, new track bar, axle joints, axle shafts, tie rod ends and hubs. I had the front end aligned and my thrust angle was off - the rear axle was cocked to one side. I have a 2.5" lift with fixed control arms, so I purchased adjustable arms for the rear and the alignment shop got all of my specs in line. I thought problem solved.
I can drive it down the highway at 70 miles per hour - no handling problems or issues. But if it rains, the rear feels loose and I cant drive over 45. It snowed here yesterday and I drove the Jeep and sure enough over 30 and it started to feel loose. I thought it might just be me, so I kept in it and it started to spin around at about 40. It acted the same in 2 or 4wd.
I am also experiencing some weird tire wear - my rear tires are wearing bad on the inside. My alignment shop said my axle is not bent. I would think if my shafts were bent I would see some leaks.
Then I took my 2 door JK out and it crusied through slush at 45mph and never felt loose. So I don't think it is just because it is a Jeep (short wheelbase, light weight, etc)
I am at a loss on what to do now. I think it may be the limited slip in the rear loading and unloading. When I hit a bump the Jeep kicks like a Detroit Locker.
Any ideas would be appreciated.

 

[Eric]

if the housing is bent, the LSD may not be working correctly, it may be in a bind and get a a little squirrely.
sounds like some wierd simptoms. never had the rear of mine feel loose, except when i drove it home from wheelin with 1 shock broke in half and the other one bent and locked up.

make sure the locker works like it is supposed to, and the LSD isnt locking and unlocking

 

[bob1340]

The tire wear is weird, but indicative of a bent axle.
The control issue in wet or ice is probably your LSD/Locker. If you want to
it can be checked by removing the rear driveshaft and running it as a front wheel drive.
If the problem is gone, then have the LSD checked out.

 

[jeepin al]

A couple of things, make sure the rear control arms are all the same lenght. Like the toe in toe out problem in the front if the rear axle is not tracking correctly it may possibly wear the inside of the tires out. If this was the case you would most likely only crab walk down the road. The rear axle would really have to be bent to wear the inside/outside of the tire out. Out side of the tire wear sounds like under inflation, however the bouncing and lost of traction feeling sounds like the tires have too much air in them. With the limit slip and the 6 speed I have in the snow and ice you need to be very easy on the clutch it will slide sideways. Same when at speed in you are in too high a gear, the torque to the back wheels will slide you around.

Interesting problem, wasn't much help but items to ponder!

 

[Herk]

On really slick surfaces in 2WD mine is a little squirrely. I can feel the limited slip in the back "hunt" transfering torque from side to side. Engage the front axle and it settles right down.

As others have mentioned, if you have slop anywhere in your suspension, the problem may become much worse. Replacing all 8 control arms made about a 9000% improvement in my Jeeps manners. Mine also seems to be sensitive to tire pressure, especially in the back.

 

[KaiserJeep]

Look closely at the condition of the rubber bushings in the control arms at both ends. The rest position should be virtually centered within the sleeve, displaced no more than 0.1" in any direction. If your bushings are off center any more than that, they are worn and allowing the axle to move around while on the road.

You could replace the stock bushings, but if you have ever had any thoughts about aftermarket arms, now would be the time to do it, since the labor costs to remove, rework, and reinstall the stock suspension arms are greater than to simply swap new arms for old.

 

[tpreston]

I plan to crawl under it this weekend and make sure the rear track bar is ok and I will take the advice to check the placement of the upper control arms. I am not going ot do too much work because we are going to be about 4 above this weekend. My garage is not heated!
The lower arms are new since I needed them to correct the thrust angle.
I have been trying to figure out the tire wear. If Jeeepn Al is right and the bad thrust angle caused my tire wear, I should be ok now and I haven't noticed it getting worse. I wonder if my problem could be caused by my tire wear - it is pretty significant. I have rotated so both front and rear have the wear pattern. I have been looking to get some AT's anyway since we get so much snow here.

Thanks for the ideas. I will keep you posted.

 

[tpreston]

Brief update for those interested.
Took the Jeep to the dealer and told them what it was doing and I thought the LS was bad. They said no, your rear is out of alignment. I showed them my alignment specs and said I dont think that is it. They looked at me like I was another idiot that thinks he knows more then them. I told them to go ahead a align it.
They realigned, drove it and said it was still doing it (I told you so!). Since I transferred the 70/70 when I bought it used, they are going to replace the rear carrier and bearings under warranty. Amazing since I have a lift, 33" tires and wheel spacers!
I think that will solve it but will have to wait until the parts come in.

 

[bojang]

Wow, nice.

 

[elpound]

Well I assume it was the carrier?

 

[Stinger]

Brief update for those interested.
Took the Jeep to the dealer and told them what it was doing and I thought the LS was bad. They said no, your rear is out of alignment. I showed them my alignment specs and said I dont think that is it. They looked at me like I was another idiot that thinks he knows more then them. I told them to go ahead a align it.
They realigned, drove it and said it was still doing it (I told you so!). Since I transferred the 70/70 when I bought it used, they are going to replace the rear carrier and bearings under warranty. Amazing since I have a lift, 33" tires and wheel spacers!
I think that will solve it but will have to wait until the parts come in.

Did it help? Don't leave us in suspense .

 

[tpreston]

They had to order the carrier so I hope to get it back from the dealer today or tomorrow.
If this doesnt fix it I don't know what else to look at. I checked the rear control arms and they looked ok. I may need to cycle the suspension and see if I notice nayhting. But I am hoping the carrier was the issue. If it is, I will post all of my symptons so maybe it and help others with their issues
I will keep you posted.

 

[CRJeepin]

It sounds like you're on the right track to getting it fixed, but if for some reason that doesn't solve it make sure your alignment included rear thrust angle. Since this is fixed for factory vehicles, some alignment shops don't measure or include it on the report but it is important, especially if you have swapped control arms (which I realize you haven't).

The reason I mention it is the unusual tire wear. If your axle isn't bent, thrust angle is the only thing I can think of that would explain why they would cup or wear unevenly.

BTW, thrust angle is the angle of your axle to the frame (when looked at from above or below). You want your axle exactly 90 degrees to the frame, obviously....I found I was out a degree or two when I put my lift on and had to adjust the rear control arms on one side to pull it back in.