This is what happens when a piece of the centering spring drops into the transmission.


Amazingly none of the other gears seem to been damaged of course the part that was damaged is NLA.

 

Yikes!

been there done that before my heart goes out to you

 

Ever since I bought my first 928 (my 90 GT) in 2011, I have left my 928s parked in either second or third gear to avoid stressing this spring.

I have been wondering lately, if we shouldn't just start pro-actively removing the springs in order to avoid this problem precisely because so many parts are NLA now.

But OTOH, I just have no desire to remove a perfectly good work transmission from a car....

 

I'm lucky. I have another gearbox from a 91 GT with a broken 5th gear.

 

But what I'd like to know is how that middle part of the first second gear was damaged. Obviously there's an issue with heat. But I don't understand the wear. I hope somebody can explain it to me.

 

These kinds of posts scare the crap out of me!! I'm about to start racing my 928 that has a very fresh GT gearbox with LSD. Is there a way to eliminate the "grenade pin" from inside a case full of NLA unobtanium? I have one of Hans' billet shifters, what about spring loading the shifter instead? If this is considered "hijacking" Kevin's thread, I apologize and am fine if it needs to me moved. Ken

 

Somewhat embarrassing. Took a ride to the shop in search of the centering spring to confirm my assessment. It's all there.

But, the new mystery is what the heck is the metal remnant we found on the bottom of the case. Keep forgetting to take a picture.

It does not appear to be a part of the transaxle. Howard is sure the reverse gear is new so somebody has been in there more than once. Once to swap the R&P.

 

Related, it is possible to retrofit the earlier style (~ before 1984) centering mechanism. I know Precision Motorwerks has done this in the past. If you have an old transaxle lying around, it would be worth an investigation.

Early Style Centering Spring

Later Style Centering Spring


This centering spring issue is a real ticking timebomb for many of us. It would seem that an external solution would be a good opportunity for one of our member inventors to come up with something. It could integrated to the shifter, or the shift rod as it leaves the case.

 

If you go forward with Tracking a manual 928, then I'd highly suggest you add a Transmission oil cooler with a circulating pump and fan.

I too have had to replace that "spring" it took out 5th gear on mine (chipped the gear set) and was just broken on another along with the Reverse spring that sits atop at the cover making it extremely hard to drive.
Fortunately they were available OEM back in 1997, the later one I purchased was after market however I don't believe he's making them any longer

Dave K.

 

Yes, pump and cooler are in the works!! Ken

 

Just received six carbon fiber synchros for my GTS transmission along with a transmission gasket kit from Greg.

 

Nice! When Greg rebuilt the transmission in my 90, I probably should have had him put the carbon fibre syncros in just for the hell of it and upgrade the PSD discs to the 91+, but alas I cheaped out and left it stock. Not that I am unhappy at all with the results though. Shifts great.