Had to have the clutch rings replaced on my W124 convertible today at 135,000 miles. I had noticed a rattling or clicking noise in reverse, and a slight delay in engaging in reverse. I had hoped there was a loose heat shield, a bad motor mount, or something simple would be the culprit. Went through significant diagnosis, finally getting the car rolling in reverse on a lift and using a probe on a stethescope to isolate the problem.

Had a good guy here in Dallas at Metropolitan Motors do the work. As a cost data point, the total was right at $1,100. Replaced four friction rings, all the seals, filter and fluid. Parts are cheap, labor isn't. He said I did it just in time. MB's will keep going when parts begin to wear out to the point that the transmission self-destructs. Lesson learned - take it and get it checked out if you suspect problems or irregularities. By the way, I had the transmission serviced at 90,000 according to spec.

Jose says the transmission is good to go for another 100K miles. Think I'll see if I can get it.