TC4 Diff gets tight when warm?
I've noticed that the rear diff on my tc4 seem to be tighter at the end of a race. After cooling down for 10 minutes it returns to a normal pressure.
I rebuilt and shimmed, nothing looked grooved or worn, and the diff was smooth, it just gets tighter when warm. After the rebuild it was OK for 4-5 runs then started getting tight again. The front (which is steel) doesn't have this problem, and I generally have the front a bit tighter than rear. I'm using the stock greases and silicones, replaced balls, washers, thrust assmbly. The problem persists. I'm running stock, rubber, on carpet. So I'm wondering.
#1. Is HEAT the problem?
#2. Should it be getting warm in the first place?
#3. Do steel diffs never do this?
#4. Do I need more Locktight on the nut?
#5. Should I buy an x-ray?
Thanks for any help you can offer,
Bigair