Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

Broken centering spring

Thread Tools
 
Search this Thread
 
Old 05-14-2024, 07:41 PM
  #1  
Kevin in Atlanta
Rennlist Member
Thread Starter
 
Kevin in Atlanta's Avatar
 
Join Date: May 2002
Location: Roswell, GA
Posts: 8,047
Received 780 Likes on 466 Posts
Default Broken centering spring

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.
Old 05-15-2024, 02:59 AM
  #2  
Michael Benno
Rennlist Member
 
Michael Benno's Avatar
 
Join Date: Mar 2015
Location: Portland, OR
Posts: 2,164
Received 831 Likes on 328 Posts
Default

Yikes!

been there done that before my heart goes out to you


The following users liked this post:
davek9 (05-15-2024)
Old 05-15-2024, 04:11 AM
  #3  
Red Flash
Burning Brakes
 
Red Flash's Avatar
 
Join Date: Jan 2012
Location: The Heartland
Posts: 877
Received 29 Likes on 24 Posts
Default

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....
Old 05-15-2024, 08:36 AM
  #4  
Kevin in Atlanta
Rennlist Member
Thread Starter
 
Kevin in Atlanta's Avatar
 
Join Date: May 2002
Location: Roswell, GA
Posts: 8,047
Received 780 Likes on 466 Posts
Default

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

Old 05-15-2024, 08:42 AM
  #5  
Kevin in Atlanta
Rennlist Member
Thread Starter
 
Kevin in Atlanta's Avatar
 
Join Date: May 2002
Location: Roswell, GA
Posts: 8,047
Received 780 Likes on 466 Posts
Default

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.
Old 05-15-2024, 10:03 AM
  #6  
Kaplan69
Advanced
 
Kaplan69's Avatar
 
Join Date: Jun 2017
Location: Grandview, Texas
Posts: 98
Received 11 Likes on 10 Posts
Default

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
Old 05-15-2024, 01:25 PM
  #7  
Kevin in Atlanta
Rennlist Member
Thread Starter
 
Kevin in Atlanta's Avatar
 
Join Date: May 2002
Location: Roswell, GA
Posts: 8,047
Received 780 Likes on 466 Posts
Default

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.

Old 05-15-2024, 01:45 PM
  #8  
Michael Benno
Rennlist Member
 
Michael Benno's Avatar
 
Join Date: Mar 2015
Location: Portland, OR
Posts: 2,164
Received 831 Likes on 328 Posts
Default

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.
Old 05-15-2024, 02:00 PM
  #9  
davek9
Rennlist Member
 
davek9's Avatar
 
Join Date: Jul 2006
Location: Bloomfield, MI
Posts: 5,134
Received 341 Likes on 187 Posts
Default

Originally Posted by Kaplan69
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
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.
The following users liked this post:
84dizzy (05-23-2024)
Old 05-16-2024, 03:12 PM
  #10  
Kaplan69
Advanced
 
Kaplan69's Avatar
 
Join Date: Jun 2017
Location: Grandview, Texas
Posts: 98
Received 11 Likes on 10 Posts
Default

Yes, pump and cooler are in the works!! Ken
The following users liked this post:
84dizzy (05-23-2024)
Old 05-23-2024, 04:12 PM
  #11  
Kevin in Atlanta
Rennlist Member
Thread Starter
 
Kevin in Atlanta's Avatar
 
Join Date: May 2002
Location: Roswell, GA
Posts: 8,047
Received 780 Likes on 466 Posts
Default Synchros de Mayo

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

The following 3 users liked this post by Kevin in Atlanta:
84dizzy (05-23-2024), Red Flash (05-23-2024), RennHarry (05-24-2024)
Old 05-23-2024, 07:54 PM
  #12  
Red Flash
Burning Brakes
 
Red Flash's Avatar
 
Join Date: Jan 2012
Location: The Heartland
Posts: 877
Received 29 Likes on 24 Posts
Default

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.



Quick Reply: Broken centering spring



All times are GMT -3. The time now is 02:38 PM.