Topic: Resistance in drivetrain when hot

[Eucalypta]

Hello fellow Jeepers.
I have a conundrum for you: My jeep has a stock engine, AX5, stock transfer case, stock axles, 33" wheels.
It runs very well for years now in this configuration. I drive it on and offroad.

This weekend; I went to wheel with some friend in Germany and had to drive about 150 miles on the freeway to get there.
The car runs great, contstant speed about 90 km/h
When I was almost on the campground, I descided to fill the tan and pulled over, filled her up and wanted to drive away.
I heard a lot of banging/knocking from under the car. I turned into a parking space and looked under: the rear  U-joint was broken. I was glad it was only that so I replaced it and wanted to drive away....again that noise.
It came, from what I could determine, from the rear axle.
When I pushed the car a bit forward or back, it seems that there is a bit of resistance and when it "runs over it" the knocking/banging sound was there.
I put the transfer case in neutral, same problem
Clutch disengaged, transmission in either speed: same problem

I called a friend and he loaded the car onto his trailer. when we arrived at the camping site, a few hours passed and the engine, transmission, axle coolled down.
We raised the rear end and turned the wheels: no sounds, no resistance. (backlash and play on axle withing specs)
I started the engine and in gear, transfer case in 2H, no sounds.
Same on the front end.
I rolled the car of the trailer: no sounds what so ever!!   
I drove it a bit around the campsite, making turns, back forth, no sounds.

Because I do not believe the Gremlin has gone; I really want to find out what is/was the problem.
Some parts in my drive train have my suspicion but I first want to know if any of you ever encountered this problem.

Looking forward to your advise!

[sharpxmen]

If it didn't go away I would have said the ring and pinion and you broke a tooth or more. it's strange to go away so I'm not sure what to tell you to do from here.

[Eucalypta]

Thnx!,

I opened the diff; oil is a bit metallic but no "pieces" of metal.
I took the diff out and apart: no wear or tear visible on theeth.

Only thing completely worn out: the limited slip discs. With diff still in housing; the plates are loose and not compressed.

Would the following be viable:
The discs are loose and the rotating discs have not many resistance from the stationairy discs when diff is cold.
When the diff heats up; the discs expand and the friction between them gets bigger; if there is no LS fluid added, the discs bind.
When I try to drive away this bond snaps and engages and snaps etc. giving strain on the drive train and making that horrible banging sound.
After cooling down, the discs contract a bit and do not bind together: banging/locking-problem seems to be gone.

If so; my problem would be worn out LS discs in combination of lack of LS fluid?

your thoughts?

[sharpxmen]

Is it an lsd or autolocking? if the latter it only compresses the discs when you have difference in torque between wheels (when one axle shaft spins will push the discs together).
or since you offroad a lot might have worn out
LS fluid is a friction enhancer and not the other way around. if you ran it without it then probably has more wear than it would have had with it.

[Eucalypta]

I replaced the LS disc packages and changed the oil, added the LS additive.
Exchanged the oil in the transmission: it was clear and no "parts or pieces" fell out.
First 90 miles: no chatter, no noise, no banging and no "locking" like before.
I do not know what the problem was, or if it indeed were the worn out LS discs in combination with the lack of LS additive: I am happy again. 
Hop I stay happy