Does anyone have any experience with this tranny problem. It seems when I bought this car, the detent spring(brings the shifter back to a neutral position when taken out of gear) is broken. I've asked my local Porsche repair shop what my options are and the response is to find a used tranny and cop the part out of it, and save the used tranny for parts in the future for a rebuild.

In my mind another option would be to get the mechanical drawing for the part, take the drawing to a machinist and have them produce the part for installation into the current tranny.

Any feedback would be appreciated.

 

talk to Roger 928's rus

 

Here's a recent discussion on the transmission centering spring.

Not sure whether an '85 would have the -03 spring or the -09 spring, look at post #32 and #33 in this thread:

https://rennlist.com/forums/928-foru...the-trans.html


Lizard 931 (Colin) has made a reproduction of the (I think) -09 spring, FWIW.

 

I feel your pain. As far as I know, I got the last one available new about 2 years ago. It's a **** poor design that is prone to failure.
Mine is post #6 in that thread.

I'm intimately familiar with this problem. I replaced mine than had to open it up because I guess I didn't set the tension right and it slipped out of the roller groove. Luckily it didn't break that time so I was able to re-use it.

There are 2 (or possibly even 3) springs. The earlier ones for the S3 and a later one for the S4. The profile is different and they are not interchangeable because the spring and the roller that it rides on have to be a set.

I think used is your only option and it's only a matter of time before it goes bad.
I'm pretty sure that never happened. Turned out it was too hard to make it and the materials weren't right.

I think someone has done something on the outside of the trans to get the shifter to return from the 1/R plane (the S3 actually rests in the 4/5 plane, not the true center. I think the S4 spring returns to center).

I think I have the WS illustration saved somewhere, let me look it up.
Edit: found em:
The early vs. late spring profile

These are the rollers:

This is where they all break (and you can see why):

This is what it's supposed to look like when installed and riding on the 'roller'

 

The update is in '86. The shifter rests in the 2-3 plane.

My '86.5 5-speed takes quite a bit of effort to get into the R-1 plane. It slides readily (what feels like) straight up into 2nd.


(Note the release bearing was improved with a better seal in '86, also.)

 

There were two different springs found in the '85/'86 transmissions.

I still have used springs (mostly all '09 style) and new springs (only '09 style.) The only spring that was available, for the years leading up to "no springs being available", was the '09 spring. Using this spring requires replacing the shifter part that this spring operates on. Failure to replace this part will quickly break the "new spring", which is the mistake that many have made.

 

I put on an external spring to pull lever to where I wanted it - has worked fine now for 18 odd rallies !!
Get the engineering head on ...........

 

Just a heads up, some of the springs being offered are welded spring steel, from what I have heard and which in my book is just asking for trouble.

There is a reason the factory riveted the parts to begin with, not because they did not have a welder.

Some one needs to make a good replacement spring for us 5 speed guys.

 

I am a little reluctant to mention the repair I made when the spring in my transmission failed as it is far from elegant and it has only been a few months and a few thousand miles since it was done.

There has to be a better and more durable way to accomplish what this spring assembly does, but finding it is beyond my imagination, skills and patience.

Details in post #18: https://rennlist.com/forums/928-foru...g-broke-2.html

Bob

 

Wow, thanks so much for the feedback! I guess my shop would rather just wait for the need to have to pull the transmission to address this. They are probably looking out for my interest, but it might be awhile before that happens since the car only has 43K miles on it. I can't see in the records where the tranny has every been pulled. I'll definitely save your experience in this to address it when the time comes.

 

This might be a false alarm, but... if the top part of the spring is broken off completely, and the lower part of the spring assembly can slide outward on the adjusting bolt, the rest of the transmission will become scrap metal.

This was true for my transmission (the broken lower part was not retained in any way), but the internals of your transmission may be different. I think that earlier transmissions might have some method of retaining the part, but I am not certain.

Anyway, you might want to be certain that this part is retained and can not move around before driving the car or even running the engine if it is not.

You might want to drain the oil and check for metal bits and pieces if you have not done so already.

Good luck.

Bob