Porsche Repair: 912 Transmission, shift linkage, bell crank

Question
I have a 1968 912 with a 4 speed manual transaxel.  I recently removed and reinstalled the engine.  I replaced the accelerator bell crank stud on the transaxel(the only change and probably unrelated).  When I drove the car I discovered that I lost the 3rd - 4th gear shift gate.  The shifter would not move into any other position than reverse and 1st and 2nd gear gates and would not move further to the right than 1st - 2nd gear. I disassembled and inspected the shift linkage from shifter to transmission and it seems to be in order (all bushings and u-joint replaced 7,000 miles ago).  I tried to shift directly at the transaxel (less shifter and linkage) with the same result. What are the possible causes and could I have caused them?

Answer
Hi Don,

Based on what you've described there can't be a "linkage" between the things you did and the symptom you're having.  I'm a bit concerned when you say you can't manually get the transaxle to shift through the gears.  That should be possible.  I' m guessing the move from 2 to 3rd gear takes more effort than you've given it.  I'm not suggesting getting a bigger hammer.  Let's leave the transaxle alone (after you make sure it's in neutral) and focus on the linkage.  

There really should be only one answer to the problem...and that would be the adjustment/connection point between the linkage and the transaxle selector shaft.  But you didn't mess with the connection because you didn't take the transaxle out to work on it, right?  And the trans shifted great before the engine was pulled, right?

Unless the 912's are radically different than 356's, which I can't imagine...there is a set screw and a pinch bolt affair where the transmission selector shaft and the linkage mate.  The adjustment is described as follows:  "Before fully tightening the rear selector lever pinch bolt make sure that the rear socket for the lower ball of the relay member is positioned so that there is equal clearance on each side of the ball with the gearshift lever in neutral."

What all that means is you should be able to sit in the drivers seat and wiggle the gearshift lever around in neutral until you begin using the knowledge you've gained from staring at that spot so long...and eyeball the point where the set-screw/pinch bolt have to be so that every gear is reachable.  You actually should be able to set it so you can only be in 3rd and 4th...and not be able to move the gearshift left to 1st or 2nd.  If you watch the interplay as the parts move against each other when everything is loose and then a little tighter and then a little tighter still...you should stumble upon the right setting.   For the money you're paying me, you should be getting better advice than "I hope you stumble onto the answer."  But it is a trial and error situation.

If the set-up of your linklage is VERY different than I've tried to describe it, write back to me and we'll have to take a few steps backwards and start again.

Dave