Shift coupler for 915?

[wevoid]

Brad,

I think "danger" is too strong a term. I doubt there is any danger of using either a universal coupler, or any style of precision bush in the shift coupler.

I too doubt that smooth shifting will accelerate wear. By far the greatest hazard to the transmission is the driver - driving style and lack of mechanical sympathy more that anything else. Any device that encourages or assists the driver in making better shifts is going to help a transmission like the 915.

It is more a matter of compromise.

The round hole bushes do not allow sufficient pre-load-free misalignment. This will add radial loads to the bearings in the shift mechanism and the bearing bore for the main shift rod where it protrudes from the transmission. This might require more frequent servicing of the shift mechanism bushes, or perhaps some long term remedial work on other parts.

The universal joints offer an unequalled balance of precision and misalignment freedom. The compromise is that these are the most expensive solution.
As with the round hole bushes, a second consideration is the potential of noise being transferred from the transmsission through the shift mechanism.

The stock components have the lost motion fore and aft, making neutral about 1" long as opposed to about 1/4" long when you install any product that eliminates the slop. The compromise in this case is the extra free play and the longer shift lever throw.

An interesting comparison between all the products mentioned here would be the longevity. New factory bushes feel good for how long? and new aftermarket bushes feel good for how long? XX brand Universal joint feels good for how long. This BB is probably one of the best resources to set up such long term tests.

With the newest, new delivered 915 coupler now 17 years old, I think it is safe to say most cars would benefit from some attention to the coupler, even if only to restore the shift mechanism to the factory intent.

Regards

Hayden

[SLR]

Ok just to day done my shift coupler bushes, from Pelican parts (the old one wasn't all that bad) but it fells smoother, getting the thing adjusted right is a fiddle though.

[Vipergrün]

Originally posted by SLR
Ok just to day done my shift coupler bushes, from Pelican parts (the old one wasn't all that bad) but it fells smoother, getting the thing adjusted right is a fiddle though.

In case you didn't try this......

Loosen the shifter coupling. Find the *sweetspot* neutral plane. Hold shifter in neutral all the way towards the drivers side (left if facing front) and at the same time, rotate the shifter coupling all the way towards the passenger side (right if facing front). Tighten the coupler. This has always worked great for me

[DanS911]

Thanks Chad I'm gonna try that

[84toy]

I machined bronze bushings for mine. I don't regret it at all and although I agree with the concept that it "could" and "should" wear things out sooner, in reality I doubt if it will be significant. The shift rod housing in the tranny is quite long and lubricated and gives plenty of bearing area. Mine shifted so smooth and precise afterwards it would be hard to say it was a mistake for the benefit it got me and the joy of precise shifting on a 915. It does transfer more noise in 5th gear when in the detent. I forgot to wrap a layer of rubber around the shift rod which I hear can reduce that issue. YMMV

[gumba]

I changed from the Fabcar coupler to the Wevo coupler. I did notice a slight improvement in shifting. Also the shifter has less fore/aft play.

[Wil Ferch]

Brad:
I'm going to re-open this thread by asking to clarify your "install" procedure.
When you say "loosen the shifter coupling"...do you mean the cross-bolt ( pinch bolt) near the shift rod closer to the front of the car? Or...do you mean the set screw on the tranny connection side....?
-Wil Ferch

[Todd Simpson]

Sorry to jump in here, but it has to be the pinch bolt. The set screw on the other side won't allow any adjustment.

[CHILI]

Yea, pinch bolt. I believe it's 13mm if I remember correctly. But, I would mark it with an exacto blade first. At least you can get back to a "starting point" if all goes to hell.
I scribed mine a few years ago, and I can still see it. It's amazing how little I moved it and how much of a difference it made.

[Vipergrün]

Hi Wil.....Pinch bolt

-Brad

[Wil Ferch]

Wow...thanks for the quick replies.... !

--Wil Ferch

[SCWDP911]

Thought I would dust off this thread for the benefit of those of us that are new. Great information I think. I have discussed the purchase of a stock coupler with the brass bushings installed with another member on the board that has one for sale. In researching it a bit more, I guess I am of the overall opinion that brass bushings in the coupler are OK. The sealer for me is now that the original thread is 3 years old, has anyone been able to clarify and qualify whether or not the brass bushings will really lend to quicker tranny demise? Did anyone ever keep track of some of the various options out there and their effect on the overall picture? Do the brass bushings really give a noticeable increase in vibration and/or noise?

Shaun84, I am definitely interested, just don't want to be disappointed. If you will give me a day here to sort this all out, I would appreciate it.

Thanks to all.

[Shaun @ Tru6]

Originally posted by v8_ranch


Shaun84, I am definitely interested, just don't want to be disappointed. If you will give me a day here to sort this all out, I would appreciate it.

Thanks to all.

no worries Shane. And if you aren't happy with it, just send it back for a refund. I stand by the brass bushings that if installed properly, that is maybe 3 times adjusted to perfection, is the best, low-cost option for great 915 shifting. But you've really got to develop a "feel" in the adjustment process. Very zen!

[randywebb]

Bill V. has had one for years. Last he said - 1 yr ago?? - there were no problems.

[paulgtr]

Originally Posted by Vipergrün

In case you didn't try this......

Loosen the shifter coupling. Find the *sweetspot* neutral plane. Hold shifter in neutral all the way towards the drivers side (left if facing front) and at the same time, rotate the shifter coupling all the way towards the passenger side (right if facing front). Tighten the coupler. This has always worked great for me

Hi folks! been searching all over the place and i found this. I ordered a stomski racing coupler from our host and plan to install it. the instructions seem straight forward enough. I am not 100% sure of the alignment/adjustment procedure? can I do this by myself? or do I need someone to hold the shift lever to the left while I twist the shaft to the right. and then I tighten the 13mm bolts at the same time?

[ivangene]

WOW - opened a 7 year old thread for this

anyhow YEA you can do it alone, but after my 4th attempt I got my sone to hold the shifter and I nailed it...dont be afraid to try try again!

I just gave a friend one of my rebuilt stock couplers tonight and will be rebuilding his to a "zero play" unit soon...Installed one in a 964 last night ... these things are pretty easy once you get the feel for it - best of luck!

[paulgtr]

thanks, I will enlist help even if it can be done alone... lol I know my limits!

[bfunke]

The 914 coupler also has round not oval bushings so it has less slop than the 911 coupler. You can get new from Porsche via several of our favorite sources.

[dicklague]

I have a Wevo coupler and love it. The stomski seems to be very similar. Adjustment is easy once you get into it. Mine has been in there for 5 years and it is great. Highly recommended.


to me it is just one of those great improvements that are way better than the original.

[paulgtr]

any tips on adjusting that you would add? I can picture the process in my head. just wondering about trying to hold everything in place and tightening the coupler.