On my 1970 280SL, I had the common problem of the automatic transmission bushing falling apart on the lower end. I order replacement bushings from Mercedes Classic Center, part number 112-268-01-50.
I followed all the advice of previous posts, and got them installed on the linkage rod with the flat end toward the post/shaft/transmission. The problem I am having now is that when pressed with much effort onto the shaft, it pops off immediatly and will not stay on. If the bushing is installed the other way with the smaller hole facing out, it goes on very easily but will probably pop off quickly and no room for a retaining clip ordered from MercedesSource.
I have not tried the suggestion I saw about soaking in hot water, but thought that was for installation into the linkage arm, not pressing onto the shaft.
Any ideas? Thanks.