Initially got a chattering from the rear when starting off making left turns. Now it happens when going straight. Not all the time; just sometimes. Any ideas? I've added the anti-slip additive a couple of times, but still happens. I don't believe the unit has ever been rebuilt. What is involved in a rebuild?

Your best move at this time is to remove the rear cover and clean out the oil and any debris that you may find. As I remember the later Dana 60s use the TracLok (sp?) carrier (the weakest of the OEM models, single casting with big windows) and it has small parts that can break and become caught up in the ring & pinion. Open it up, clean & inspect with a fresh oil fill will cost less than $20.00 and at least you will know where you stand. Do it now!!

yea maybe some condensation build up that will cause chatter.

make sure the vent is working!

I used to replace my own clutches borrowed and rear end spreader.

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Make sure you use the right lube sure grips need the right lube plus additives.

yes, the clutches can be changed out in the car, not easy tho..

with the chatter on turns, it is most likely a wrong lube and or additive..

Must use the expensive additive, and premium lube...

Chatter going forward is not releated the clutches tho, like suggested, jack it up, pull the cover and inspect the gear teeth to see what is going on.

Will do. Thanks.