Hi,

I just bought a 1994 E320 and I'm giving it a good once over. It has a light clunk when I abruptly chop the throttle and it goes from accelerating to decelerating.

Once I find a 14 mm hex socket, I'm going to do a differential lube change. I've chosen to replace whatever is in there with Mobil 1 70/95 synthetic. I don't want to start up the debate over synthetic vs. petroleum, but that's what I decided to get.

I climbed underneath last night to inspect the flex disks. The front disk was obviously new, but the rear was not. There is some slight cracking of the rubber around the thicker areas where the bolts pass through. I didn't see any indications of separation though and I couldn't flex it by twisting the driveshaft by hand. I also put both wheels in the air and spun the diff by the driveshaft, then each wheel. There was no excessive slop or clanging.

I am hoping that the new gear lube will do the trick, but can anybody tell me how to tell if the flex joint is good or bad?

Thanks, Dennis