After running down the highway for a couple of hours, and I try to make a tight corner like in a parking lot, it feels like the rear diff is not slipping. almost like it wants to push truck straight ahead. It clunks than lets go and I turn okay. 2wd truck, am I supposed to use special addititive to diff oil?

 

If you have the limited slip diff, you need to make sure you add a friction modifier in the appropriate quantities.

 

That is a commin sign of clutch failure. The repair is not a big deal as long as they have the proper install tool.

 

if it is a common sign of clutch failure then mine has been failing since new about 80k ago.

 

I get the same thing but only in reverse, is it a problem? It feels like the diff is actually locked up, on gravel it always turns up the road on the inside tire. I was going with the don't worry about solution...