Welcome!

You say clunk from diff? If its a slight clunk when coming off throttle this sounds normal rather then a common fault. Unless something is seriously wrong, the common fault (which isnt too common) is it starts to leak the fluid from the drain plug.

The cruise control lifting up the pedal technique is a trait through the whole of the 75/ZT range, and its only a slight nudge up from the pedal thats needed.