well my car is all but done, fixed the turbos blowin oil (was a drainage problem), ran coolant to the turbos (hope its works) and i had the 3:55's installed and took the 4:10's out. well, last winter my mechanic told me that my clutches need replaced. I asked my mechanic if when he installed the 3:55's if he went ahead and replaced the clutches. he told me that auburn rear diffs dont have clutches, its some sort of other kind of setup (he knows what it is but i dont), but that if its goin bad i have to replace the whole diff. is this correct? are they rebuildable?