Transmission questions, Shifter fork tolerance Options

[Bartlett 914]

I am rebuilding my transmission. The only real problem is the first / reverse operating sleeve. I had one on the shelf and a new syncro ring. The transmission had a problem jumping out of first. While I was there, I made some measurements. The shifter forks fit in the operating sleeves in a groove. There are 2 measurements I made. One is the wear on the thickness of the fork and how much slop there is in the groove. I used feeler gages to measure this. The other wear in more of a diameter of the shifter fork. As it wears the diameteter gets larger and the fork can rock in the sleeve. Here is a picture how I measured this.



The side clearence: Would rock (diameter wear)
first / reverse .010" .028"

Second / Third .003" .060"

Fourth / Fifth .003" .060"

It appears to me that the First / Reverse is worn thin. I think it is in specs.

The other 2 seem to be worn in a diameter (fork would rock back and forth) maybe a bit too much. Can anyone tell me if these forks are O.K.?

[Cap'n Krusty]

Sorry I'm late to this discussion. Been out having a life ........

In the over 35 years I've been doing Porsche trannies, I've never seen a worn shift fork related shifting problem other than with the steel forks in early 356s. Bent ones, maybe. You need the slop to keep the fork from exerting unwanted pressure on the slider when it's not being shifted. You really need to use a fixture to align the rails and forks, and the 4mm spacing tool that goes along with it. Centering the fork/slider combination between the gears is done by eye, as is the rotational position of the fork on the rail. EVERY case of popping out of gear I've seen (except for the ones caused by missing coupler bushings) has been caused by worn dog teeth. Look at the slider and the gear. If the teeth aren't sharp and well defined, they need to be replaced. You can usually compare them with 4th or 5th gear dog teeth and spot the bad ones. The Cap'n