May not be of broad interest, but I fixed up my sloppy shifter mechanism.
I have a 300E, for which the 5-speed is rare, at least in the US. I understand this tranny is used on other models, so someone out there may benefit from my experience.
Sloppy shifter. Lots of free play. Sometimes difficult to engage 5th, in particular. Overall miserable and vague shifter feel. From external observation, appeared that there was a lot of play in 'fork' bushings (#26).
#20 "fork" repair kit
#53 "Barrel Pin"
Started by removing entire mechanism from car.
Right away on the bench, it was pretty clear that the levers (#95,#104,#113) were binding, and not moving freely independent of each other. Fork mechanism was a bit stiff, but did not appear to be the root problem. Fork bushings did not appear worn, as expected.
1) Took notes, and marked the orientation of everything carefully. Mechanism is obviously quite complicated. Attached diagram was essential!
2) Took everything apart.
3) Found a lot of corrosion and debris on shift lever 'faces', where they rub on each other. Also on metal washers #83 and #89. Cleaned and sanded smooth. Applied synthetic moly "brake grease" to all of these metal to metal rubbing surfaces. This part of the mechanism is exposed to the elements.
4) Found that 'metal slide barrel'(#47) and pin (#53) were not worn in any significant way, which surprised me.
5) Plastic spacer (#77) was a bit worn, but I was able to turn it over.
6) 'Plastic Housing' (#14) was worn around barrel to some extent, and I wish I had ordered a new one. Iwas able to take in most of this play by pressing in the new fork bushings(#26) further than I found them, such that bushings were in gentle contact with barrel. Not the way this was designed to be done, but it really worked great!
7) Nothing in the fork repair kit (#20) actually needed replacement. None of these components were worn. A clean and lube would have done it. The bushings (#26) I suspected were not actually worn, they are designed to allow some give under load. The root problem was that there was too much load on them from the binding levers.
8) Every moving part got a careful clean and lube upon assembly. Most parts got silicone grease, except the exposed metal-to-metal levers and barrel, which got synthetic brake grease.
An unbelievable difference! I had thought that a tired tranny @200k was a big part of the problem, but after this, it feels surprisingly tight and smooth. Loving the 5 speed now!
Knowing what I know now, I would have purchased and replaced:
#14 'Plastic Housing'
#83 'Metal Washers' x2
#89 'Metal Spring Washers' x2
The parts I bought were not really needed.
Best of luck.
Hope someone finds this info useful.