I had the same problem (no reverse) in my '76 450SLC. I had asked my friend who now does only bakes/front end work and he said he didn't know what was wrong but would look into it. Since he no longer does full mechanic work I didn't want to impose upon him so I took it to one of those "only work on transmission places" and asked if they could take a look and tell me if the problem was internal or external. They told me it was internal and would have to rebuild the unit. I opted not to do that at the time. The next day I took the car to have the balancing/alignment etc. done and my friend handed me a piece of paper. It was an email that explained how to adjust the band externally. He had asked a friend, who is very into MBs, just what the problem was.. and his friend had gotten the info, and printed it out for me. Now, I'm not saying the "transmission place" people were dishonest, I just don't think they had the knowledge to handle the situation. I had asked if they worked on MB Xmissions and they assured me they knew all about them. Obviously not. It's nice to have friends and honest people around you. Since the incident I have passed this knowledge on to other MB owners hoping it may save someone a rebuild when all they might need is an adjustment.
