I'm guessing it's ring and pinion. The other day when I started to drive Old Yeller the Auburn limited slip started locking up and strange sounds could be heard coming from the rear end. I immediately parked the truck.
Today I pulled the oil fill plug on the rear diff and checked the oil level. It was close to full. Then I took the trany out of gear (posi still locks the axle down when trany is in gear) and rotated the tires and that's when I could hear the clunking. It was noisiest on the right so I pulled the tire off and can push/pull the axle in and out about 3/4 to 1". I didn't have time to pull the rear diff cover.
I suppose it could be the posi unit but given the cost I'm hoping this simply a broken ring and pinion.
Too many hard launches.
