2000 Wrangler "clunks" at initial motion

[don.j.pearson]

I've got a 2000 4WD Wrangler with 20K miles on it. Bought it new. It also has the locking differential. During the past few couple of years, I've noticed a repetitive clunking sound occassionally when I back the vehicle up. It's more pronounced when the vehicle has been driven and is warmed up. It also happens sometimes when turning (not hard turns). When it does clunk, it will do so for maybe 2 or 3 seconds and then goes away. This is an intermittent problem and, of course, the dealer could find nothing wrong with it. Other than this annoyance, the Jeep is in excellent shape and has been "babied" as far as offroading is concerned. I don't think the clunking is due to the rear drum brakes chattering nor do I think it's due to the emergency brake release, since it'll happen after driving around for 20 minutes. Sound appears to be coming from the rear. Anyone with similar experience???? My email is [email protected]

[Bronco2]

I am not a jeep expert,it sounds like the clutches in the differential hanging.I have had this problem before with other cars.If you have a local rear end guy,ask him what he uses as a "friction modifier/limited slip additive " NAPA sells a good product,but I would double the amount.Use a suction gun to remove enough oil.You could drop the cover and change the oil,but it is probably filled with synthetic which gets expensive quick. Check your manuel or the local parts store for specs.Also,I have not seen the clunking really hurt anything,its just annoying