If it were mine, I don't think I'd go for a used tranny without first doing some homework. I would go to a good Indy tranny shop, one that's experienced with Mercedes, and have yours evaluated. You'll hope the problem is a switch, as suggested in the previous response, but if it isn't you can find out what it will take to repair what you have. You know your transmission but you don't know the history of the "used" one you're considering. In the alternative, you may want to consider a "rebuilt" as one of your options.

As for information on Trannys that will fit your car, I'd call the "Sun Valley Mercedes Dismantlers" who make a business of rebuilding Mercedes trannys and they claim to know every Mercedes tranny in the book. Their telephone number is 1-818-768-0704. In the alternative, they respond to emails and their address is SVMBZ@aol.com. I have found them to be very knowledgeable and helpful.

I hope this helps,
William