My 450SLC was starting to slip a little in reverse, especially under load (e.g. up a hill).   The transmission was shifting gears very well other than this one area, and the fluid looked clean and at the right level.

The 450SLC uses the 722.0 transmission, which unlike the later models has an adjustable B3 Band (which is used for engaging reverse).   This was not something I was aware of, but I was able to find threads on various Mercedes forums outlining how people who had similar issues had been able to adjust this band to cure them.   I wonder how many perfectly good cars were junked instead of trying this simple adjustment?

This can be accessed from under the car, on the drivers (RHD) side.   There is a bolt that can be tightened up to adjust the band.  It is quite hard to get to and you can feel it more than see it.

The photo above shows a socket on the adjustment point.   So far the adjustment seems to have worked, I’ll see how it goes over the next few weeks.