First of all, I have a 2000 f-150 x-cab 4x4, 3.55 LS. When ever I make slow turns in either direction, it grinds and shakes the whole truck. It does the same going in forward or reverse. I have taken it to the dealer (under warranty) FOUR times, but I think they have finally fixed the problem by replacing the whole differential and gears for the second time. I spoke with the lead mechanic and he said that this is a common problem with all the ford trucks. He said that most of the time they just add friction modifier and it does the trick. The other approximately 5% he said they replace the diff. and it fixes the problem. I just wanted to know if anyone else has been having the same problems as I, since this seems to be fairly common.

 

If you run a search you will find TONS of people that have had this problem... Rest assured you are not alone here. I think there's some putz at the shop that builds the axles for our trucks that doesn't know there's supposed to be anything different in the limited slip gear oil...

Welcome to the board.

-Joe-