4spd POPS OUT OF FIRST
 

I purchased a used 930 4spd and had a chance to try it in the car. It works great, except for poping out of first when you release the clutch. If you lightly hold the shifter you can keep it in first then after shifting out it will stay in the other gears fine. Anyone know what the problem is or a direction to head in? Thanks

First, make sure everything is adjusted properly. A misaligned shift coupler could be the culprit.

The past owner had the car into a shop and was told everything was adjusted right and the trans needed repair, said they wouldn't know what was wrong until they had it apart. This is when the $$$$ start adding up.

Sounds like the synchro slider treeth and gear selector teeth may be worn out, rounded off, or some broken off and they are not locking into each other anymore.
When that happens the synchro slider slips off the gear selector teeth and it pops out of gear under load.

On Borg Warner synchros there are 3 spring loaded tabs that are under the slider in the synchro hub.
They help hold the synchro slider in place engaged with the gear selector teeth.
I don't know if porsche synchros have those 3 tabs.

Can't say I know anything about the 930 transmission - BUT I have an 84 911 and was told by various shops that I would need a new transmission sooner than later. Shifting was a bit messy and it really impacted my enjoyment of the car. Then it started popping out of 1st and I decided that I would need to replace the tranny.... but first I decided to check out the shift coupling for kicks. I spend about 30 minutes adjusting AND VOILA - my car shifted beautifully and no more popping out of first. So much for the experts! After examining things a bit I discovered that the shift lever was bumping up against the front of the Shift Housing and not letting me get fully into 1st. The adjustment solved that and other seemingly huge problems.

My theory is that adjusting the shift coupling takes a bit of patience and "love" - something that shops and non-owners tend to lack.... So try the adjustment first before jumping into spending the big $$$$.....

Best of luck.

JCSJCS

+ 1 on the shift coupling.

Do you feel any clutch chatter/vibration as you release the pedal? The only time mine ever poped out of first was due to the clutch bowden tube not having enough bend. I was experimenting with various cable adjustments and evidentally didn't get that one right! Vibrated the damn thing right out of gear! Also, taking a few moments to check the coupler adjustment is a good idea.

Compliments of John Walkers Workshop:

Thanks for the info everyone. The trans is now out of the donor car so I can't try it anymore. After opening it up I found nothing that looked worn. Put it back together and it shifts great on the bench, so hopefully it was just the shifter set up.

If it has been taken apart someone flipped the op sleeve on 1/2nd. There is one way it goes and if you do it the other way it does not allow full engagement on the sleeve. If that has not occurred then the op sleeve is worn and has waves in it if you will that is causing it to jump off the syncro. The problem is statically it is not going to do it until it is loaded up therfore the bench test probably is not going to be helpful.

sounds like the hub is getting worn for 1st gear allowing it to pop out. if its popping when you lift off the throttle more than anything its the hub.

Stephen how do I know which end is which? When I looked inside nothing looked worn and the sleeve didn't seem marred or have waves.

DSPturtle did this. He posted about it here.