Diff is S4 clutch type LSD with TONS of miles on it.

So my burgundy beast had been sitting for a good while... I tell my friend he can borrow it for a month so before he takes it I drive it around to make sure everything was sound. One thing I noticed is that the diff or drive shaft would clunk a little bit letting the clutch out while taking off in first gear.

Fast forward to today, I go to pick the car up after letting him borrow it, and I immediately notice when I tried to make a u-turn the rear wheels were hoping and skipping and clunking as if it was a full locked or welded diff.

So I get the rear end off the ground and I go to spin the tires and sure enough the tires are completely locked together... I tried with a big guy to get the other tire to spin the opposite direction and it wouldn't budge at all... as if it was welded or something.

Friend says didn't happen to him while he was driving it as if this problem happened during the time he parked the car and the time I went to go get it.

Again diff is S4 LSD with lots of miles on it, the LSD hardy worked at all when I was daily driving the car, it is really worn out.

Anyways any thoughts what would cause it to "weld" it's self? I have driven on welded diffs before and this acts just like a welded diff but with worse low speed symptoms.

Thanks for any help.

 

Check your fluid, if it's full of metal... GUESS WHAT! Time for a rebuild or another diff. Others will know more about this though.

I do feel obligated to ask if you checked other suspension components and drive train mounts, so, did you?

 

Just checked under the car real quick haven't got it on my lift yet will do so soon. Everything looked normal as far as I can tell checking in the middle of the night while it is pouring rain with a little flashlight lol.