just changed the spyders in my '99 silverado 1500. they were junk@156,000. were they a weak point in the diff? seems i've talked to a lot of guys that have changed them. bought the truck used and always noticed a clunk when i put it in reverse. gotta fill it with gear oil and try it out. maybe reverse clunk is gone. i know the bang it made going around a corner will be gone.