912E transmission rebuild

jshape · jshape's Garage

I've just purchased a Porsche 912E and am really happy with the car. Yeah, the power is not all that great but I'm not into racing as much as I am having a fun car to drive. The car could stand to have the transmission beefed up a bit. There is a bit of crunching between 1-2; 2-3 and in downshifts if you don't pause in N for a bit. Sounds like the synchros are worn. I'm not inclined to handle this myself -- I'll stick to changing plugs and minor tune-up stuff, but I would like to know if any of you out there in 912E land have gone through this before and would like to get an idea of how much this should cost me. I have yet to look around here for a shop to do the work as I've put the car into storage until spring. This is my first Porsche and my goal is to keep it a reliable and enjoyable summer daily/weekend driver for many years. Any other suggestions or comments would be welcomed.

piperpilotduane · 11-20-2001, 09:35 AM

Welcome to the world of 912E only!! The transmission in this car is designated as a 923 put in the 912E only!. It has a different gear ratio than the 915 transmission in a 911. If your gears are OK the syncros should not be hard to find. Find a local shop to do the work so you know that you get your 923 transmission back. The input shaft on the 915 is different and will not work.
911 racers love to get hold of the 923 transmissions and change to a 915 input shaft for racing. The gear ratio is lower and gives them more torque to the ground. Good luck!

jshape · jshape's Garage

Thanks for the information. Hopefully, I can find someone here who can do the work!

PorscheDV · 01-15-2002, 01:06 PM

what you posted caught my eye...is that all thats needed to get the 923 up to the task of handling more TQ? i always hear of the 901 pitfalls as far as TQ....so the ratios are better? how do i beef it up? just the 915 shaft huh? what will it be able to handle then?

piperpilotduane · 01-16-2002, 03:03 PM

It is my understanding that they change the input shaft to mate it to a 6 cyl engine. The 1-4 th gear ratios are diffrent and allow higher rev's and torque in corners. This info was told to me by a PCA racer that claims to use this setup. My previous comment about torque to the ground was because of the higher RPM's at the lower speeds. As far as mechanically handleing the torque better I do not know. I hope my posting was not misleading to you.