What do you think of my shift coupler bushing ?

Deschodt · 07-15-2009, 03:31 AM

Leave alone or replace?

Huge amount of slop, in my opinion... That said, the reason I ask is that it seems to have been designed that way (not round, flat on top and bottom) to provide some "give" horizontally... The replacement part from our host is definitely round with zero slop.

And I read somewhere else that "The original factory bushings had oval holes, if the holes were round and there was no freeplay fore and aft, you'll kill your syncros with drag and side loading" and "without the oval holes you are susceptible to kicking out of gear when you fly over railroad tracks, potholes, obstacles..."

Soooo, good advice or phooey? Slop or no slop ? That car is a 69 912, I know, 911 board and all... but there is little traffic on 912 board and it's probably not 912 specific... Besides my 911 is next so I might as well get an answer now! ;-)

Thanks !

emac · emac's Garage

Greg
Not the expert, but I would replace. You have the coupler out and the new parts on hand.

trak ratt · 07-15-2009, 04:18 AM

Hard to tell when they wear out unless there is visible damage. But it’s out, new ones are cheep, and unless you know it’s been replaced in the last 10 years or so why not? Don’t forget the one at the bottom of the shifter and in the tunnel on the shift tube.

tswaney · tswaney's Garage

I'm no expert either, but agree that since the coupler is already out, go ahead and replace bushings. I did mine a few months ago and it really wasn't very difficult.

rattlsnak · rattlsnak's Garage

youre going to get slop with the new one. go with a WEVO.....

tonythetarga · 07-15-2009, 05:27 AM

Agreed, you will get slop with the new one. I went with the brass inserts bought through our host and have been very happy.

Bill Verburg · Bill Verburg's Garage

I had these made but I believe that they can now be purchased, Also had a guide bushing made w/ zero slop

the only other thing to add is a Wevo clamp

Of course you can also use Wevo or Stomski coupler

Deschodt · 07-15-2009, 06:33 AM

Cool, that seems to indicate that zero slop is better and the small gap "designed to protect syncros" argument is BS... Kinda what I thought...

I don't want to go with solid mounts on the 912, that car is my "smooth & comfy ride" and my wife drives it as well and likes it just because it's comfy that way (she won't touch the 911 gearbox)... I would do so with the 911 but not the twelve ;-) Thanks !

FPB111 · 07-15-2009, 10:09 AM

Wonder why Porsche designed the bushing with oval holes? It probably cost more to do that and made an already vauge shift linkage more so.
Maybe they felt the coupling needed a little slop to keep pressure off the syncros. Maybe a slightly misadjusted shifter would pull the trans out of gear under accel/decel with well broken in trans/engine mounts? Maybe the shifter rod/lever/knob assy vibrated excessively during highway cruising causing premature wear on all of the linkage components?
NAH BS! Probably the engineer assigned to shift linkage design just did not know what he was doing.

RoninLB · 07-15-2009, 10:19 AM

Quote:

Originally Posted by FPB111

Wonder why Porsche designed the bushing with oval holes?

to my understanding it's to make the shifter user friendly by eliminating tranny vibrations passed through

Deschodt · 07-15-2009, 10:20 AM

Quote:

Originally Posted by FPB111

Wonder why Porsche designed the bushing with oval holes? It probably cost more to do that and made an already vauge shift linkage more so.
Maybe they felt the coupling needed a little slop to keep pressure off the syncros. Maybe a slightly misadjusted shifter would pull the trans out of gear under accel/decel with well broken in trans/engine mounts? Maybe the shifter rod/lever/knob assy vibrated excessively during highway cruising causing premature wear on all of the linkage components?
NAH BS! Probably the engineer assigned to shift linkage design just did not know what he was doing.

That is sarcasm, right ? ;-)

The thing is, every replacement coupler I've seen has been a solid one with even less give than my new plastic round bushing. So if the solid ones made the car pull out of gear so easily, we'd have heard about it by now, no ? The wevo one, the stomski (sp?) one, solid bushings.....

Anyway, I don't know, which is why I was asking... If you think that my current red bushing is actually OK, please say so without the sarcasm, just so that I am sure what you mean ;-) Could well be mine is more correct but still worn out, you know what I mean ? And all the new ones are round ! What's a guy to do ?

FPB111 · 11:25 AM

Sorry for the sarcasm This is what set me off:

"Cool, that seems to indicate that zero slop is better and the small gap "designed to protect syncros" argument is BS... Kinda what I thought... "

Stock 911 shift linkage is imprecise at best. Yes it can be improved if all bushings are tightened up some. If you do this you and do not want to create some other problems you should tune (blueprint) all items that can effect shift action, syncro, shift fork longevity etc. This includes engine/trans mounts, linkage adjustment etc... Porsche would not want to have any loading on linkage, forks, syncros that could cause Noise Vibration Harshness (NVH) or wear problems that would = warranty $$.
If you have ever played around with setting up your gear selector you know that 1/8" or a couple splines at the coupling are magnified many times at the knob.

I would be very surprised if MR Verburg just put the bronze/brass bushings in without inspecting the whole system and correcting to exact specs.

As RoninLB stated strong rumor has it that the oval bushings were to reduce/eliminate NVH (and wear) in the forward linkage.

It is hard to tell if your bushings are worn out of tolerance they do not look bad.
If you have not already added a factory short shift kit you might consider it.

Deschodt · 07-15-2009, 11:24 AM

Quote:

Originally Posted by FPB111

Sorry for the sarcasm This is what set me off:

"Cool, that seems to indicate that zero slop is better and the small gap "designed to protect syncros" argument is BS... Kinda what I thought... " It is hard to tell if your bushings are worn out of tolerance they do not look bad.

Understood... Too strong a word, but I was going with the majority of opinions here and on the 912 board ;-) But on the flip side ALL the new couplers and new bushings out there are round. Then everyone else looking at my bushing says they are shot... So maybe a little slop is good but in my case it's too much slop ?

Anyway, I truly think that the solution to my problem (not mentioned here maybe, but basically the shifter rattles a lot in gears poitning backwards - 2nd and 4th-, the car sometimes jumps out of gear when driving over big bumps or train tracks, a common 912 trait) will be the early 911 tranny mount I just acquired along with new bushings for that... My tranny is moving too much front to back...

I can totally see your point where a little horizontal slop would protect both the driveline and the shifter movements, but you should see how much my shifter must move now before the coupler actually "couples" both sides of the mechanism... It's almost 1 inch before shifter movement translates into Front coupler to rear coupler movement....

The way I see this now, the damn thing is out and will be fun (not) to reinstall and adjust, so I might as well replace the bushings... Since those are plastic they will ovalize in no time anyway, there will be a lot more slop than if I'd gone stomski or Wevo or solid bushes... So all in all, I should not create too much of an issue... But ultimately my money is on the 911 mounts to resolve my problem...

Laneco · 07-15-2009, 11:26 AM

Quote:

Originally Posted by Deschodt

Anyway, I don't know, which is why I was asking... If you think that my current red bushing is actually OK, please say so without the sarcasm, just so that I am sure what you mean ;-) Could well be mine is more correct but still worn out, you know what I mean ? And all the new ones are round ! What's a guy to do ?

Just to clarify. Your bushing is a worn out piece of ****.

Replace it.

angela

Deschodt · 07-15-2009, 11:28 AM

Quote:

Originally Posted by Laneco

Just to clarify. Your bushing is a worn out piece of ****.

Replace it.

angela

Now see that, I understand ! unequivocal !!! ;-) thanks ! It's coming off somehow !

Bill Verburg · Bill Verburg's Garage

Don't forget to check the plastic cup that the lever ball rides in, they inevitably fail right after you butten it all back up.

Laneco · 07-15-2009, 11:31 AM

You will be pleasantly surprised at the improved shift feel. Don't forget to check the cup bushing under the shifter and the bushing in the tunnel (linkage goes thru the bushing).

If you already bought all the bushings as a set, just replace them all. If the other two are even slightly suspect, now's the time to replace them as well!

edit - DOH! Bill typed quicker than I did... sorry to be redundant.
angela

Deschodt · 07-15-2009, 11:47 AM

Everything is new... Shifter cup, bushing for the shift rod, now the coupler ones, and I have a 911 style tranny mount with new bushings too, plus the now redundant 912 style tranny mounts (new) will be recycled as new motor mounts.... If it still does it after all that, it can only be suspension related...

Carrerax · 07-15-2009, 12:03 PM

what is everyones opinion of the Wevo coupler? I want to make my car shift as good as possible w/o using a Wevo SS because it still needs to shift easily for my wife. Is the wevo coupler worth it or should I just make brass bushings similar to the plastic ones (PP is out and doesnt expect more for a long time).

Ray_G · Ray_G's Garage

I guess that I am going to ask you to send me your red ones once you get them out. I want them. I replaced mine with the ones you have in the photo from Pelican. My shifter was so stiff that I removed the coupler and made the holes bigger to get the thing to shift better. If I had to do it all over the cup in the bottom of the shifter would be all that I would replace. I know, I am most likely off my rocker, but those round ones made my 911 shift very hard.