Centerinjg Flange

[chumps]

I have a 1971 280 SL. The inside locking ring that holds the strong spring in the centering flange broke. This allowed the spring to recede backward which allowed the centering bushing to back off the centering shaft coming from the transmission. I discovered this when my drive line started to vibrate. I was looking at the flex disk as the possible problem for the vibration.  It looked fine so I search farther and found the broken lock ring. I assembled the engine, trans and drive line about 15 years ago (about 12,000 miles ago). I have had no problems until now. A month ago I changed all of the motor mounts. I noticed the vibration after about 200 miles. After taking everything apart I found nothing assembled wrong. I'm looking for any suggestions as to what might have caused this to happen. It was not dry, there was grease in the flange. Also does anybody have a good used flange out there? I doubt that I could find a new locking ring, It appears to be a special ring for this purpose only. If I did locate one I don't have the ability to install it (the spring is a very strong spring an I don't have the equipment to compress it and install the lock ring). Thank you for any help.
Chumps   

[ctaylor738]

It doesn't seem to be available from Mercedes, but it's a 30 x 1.2 mm snap ring, so it should not be too hard to find something that will work.  I went through this on my 280 project, and I recall that it wasn't difficult to compress the spring with my bench vise and a socket as a spacer.

[wwheeler]

I think that the ring is available from the Classic Center. I just bought all new parts for that assembly last year. Might give them a shot. They also sell the flange new as well.

Snap rings are basically a spring. And like all springs, can fatigue and break. Split lock washers and wave washers are also the same. After seeing reused lock washers break after reinstalling, I now try to use new when possible.

Hydrogen embrittlement that comes from plating spring steel parts, can also cause springs to fail.   

[George Des]

I posted last week on how I went about reassembling the cross piece including how I went about reinserting the snap ring. The snap ring on mine did not look like a std snap ring though. It had what looked like serrated inner edges. Perhaps a std one the size Chuck mentions will also work.

[chumps]

Thank you for your replies. George, the snap ring does look different it has some small protrusions on the inside edge. I suppose they are there to give a little more surface area to retain the spring. I will check with the Classic Center as to their availability.I'm still at a loss as to what might have caused this to happen. The motor mount that I put in did not look like the one I took out. The one I took out had a rubber skirt covering it and was 1/4" to 1/2" flatter than the new one. The new one looked like the front mounts. I assumed that it was a newer design and the difference in the height was due to compression of the old one. Are there different mounts for auto and manual transmissions. Thank you, Chumps

[wwheeler]

As far as mounts are concerened, there is an early and a late style. I do not believe they are interchangeable.

Yes, the ring has those protrusuions. That is the one I got from the CC.