I had a shop put in a rebuilt rear LS differential with all new parts, bearings, seals, pinion etc. I went to pick it up and drove it around a few miles and the slow speed turning chatter started. I took it back and had the shop manager drive it around the parking lot and same chatter. He then started trying to convince me that it was my transmission which never had a problem before (shaking head) . I was thinking bad clutch packs. They pulled it back into the garage and apparently put in a bottle of friction modifier, then gave me a loaner so I went back home. Next morning they call and say it no longer has the chatter. I pick it up but didn't have time to drive it much until the next day, Saturday, and it started out good, but then after a few miles, it started again. Sunday I drive it again and notice that all is well until I've went about 15 miles, then its starts the low speed turning chatter. Basically on take off when turning. It didn't seem to do it going a straight take off. I'm thinking bad clutch packs but since the fluid temperature seems to be the difference, I'm not sure. Its about 30 degrees outside if that matters.
Anyone have any thoughts about this?

 

Only experience I've had with limited slip is when clutch paks have been worn out they will chatter on turns....Mine was caused by the non use of friction modifer multiple times by the shop servicing the rear axle.
Something tells me clutch paks were not replaced or installed incorrectly or as you stated they added modfier only when you went back?? If they indeed added the modifier only after the actual service it may take a few miles for the modifier to seat in to the clutches. Key here is turning corners for some miles?? not all day driving ??

 

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Correct, not all day driving. They didn't think it needed modifier since the gear oil had it already. I had the same thought about it taking some time as I have no idea whether the clutches were soaked before they were installed. I think I'll report back to them that it's is still happening but I'll keep it for a couple of weeks to give it time to get into the clutches. But the fluid temp thing has me thrown off.
Thanks again

 

Not a good sign when they say this: He then started trying to convince me that it was my transmission which never had a problem before (shaking head)

Which makes me think he knows things are not right, but does not want to address it........... I would think it would not take much time.....like doing a bunch of figure 8s. Then the additive should be on the clutches.
Also 30 degree temp should have no bearing...... hope you get it figured out. Good luck

 

I believe he got the trans thing from whatever system it is that gives the most common resolution to the issue, but I doubt he mentioned the part where only in a slow speed turn. I agree he is trying to not address it.
I only mention the outside temp as that might have some bearing on how long it takes the fluid to get up to temp.
I'm mostly wondering why it takes driving 15 miles before it starts the shutter?
Thanks for the reply.

 

It needs more friction modifier
The friction modifier that comes pre mixed with the gear oil is insufficient

 

When I took it back, they added one bottle I believe he said. It needs 2 though correct? 8oz total?

 

That has been my experience
Most need at least 2 little bottles of the stinky stuff

 

Ok I had the shop put in another 4oz bottle of friction modifier. I'll drive it some in the next couple of days and do some parking lot circles and see how it goes. I hope this works. I will report back with results for future reference.