87 911 G50 Shift issue after clutch replacement

[Mr.Ebola]

I recently replaced a clutch in a 87 911 carrera because the rubber bushing on the OEM clutch disk failed. The car drove perfectly fine before, just the loud click when letting out the clutch due to the bushing. After replacing clutch disk(updated spring type), pressure plate, release bearing, pilot bearing, and resurfacing the flywheel, everything went in smoothly. Now the worst, with the car running I can not get into 1st or 2nd or reverse. I can force it into 3rd 4th and 5th but it has to be forced. when the car is off, i can go into all gears smoothly.

If i put it in 1st gear with the car off, i can start the car with no serious jolt, from there the clutch feels normal, once i take it out of 1st, it will not go back in.

I have replaced many clutches on various cars and have never had an issue, i am hoping there is a common issue or maybe someone has experienced this.

I vacuum bled the hydraulic system completely.

clutch kit part # 950 116 911 01

[RedCoupe]

Obviously, it's not not completely disengaging. How much did you take off of the flywheel? Perhaps one of our pros can chime in with specific help here, but I'm thinking that somehow you're not getting a full stroke of the release fork.

[Mr.Ebola]

Exactly, i believe its not completely disengaging. even tho i can see it. I had a friend press the clutch pedal down while i looked inside the inspection slot and saw the fork pulling the release bearing quite a bit. I feel like something magically happened besides the clutch opp. could contaminated transmission fluid cause the transmission not to go into gear? I'm literally desperate for recommendations right now before i pull the engine and trans back out. and even if i do, I dont think ill find anything.

[Mr.Ebola]

Im not sure how much they took off the flywheel, im sure it was not much. i wonder if taking too much off would cause issues.

[Cory M]

I had a similar issue a few years back and adjusting the height of the clutch pedal fixed it and allowed full engagement. I don't remember exactly but believe the adjustment is on the floor behind the pedal.

[john walker's workshop]

Pressure bleed the clutch system. If you surface the friction surface, you need to remove the same amount from the ledge that the pressure plate sits on, fwiw. Doesn't look like that was done, although it wouldn't cause your problem.

[Mr.Ebola]

Thanks for the info john, also, if the clutch pedal feels perfectly fine with lots of pressure after i vacuum bled the system from the slave, your saying there could still be an air issue due to the fact that i did not pressure bleed from the reservoir?

[john walker's workshop]

Most likely. Just takes a bubble or two to keep it from disengaging all the way. Never had any luck bleeding any way other than pressure.

[Mr.Ebola]

Will do first thing in the morning and report back.

[proporsche]

i might be wrong but back in the 1980`s we were told the flywheel on 87-89 should not be shaved...the only thing could be as John W said shave the pres plate....You should really ask how much they took off.....

Ivan

[Mr.Ebola]

Well it looks like i will be replacing the flywheel if i find nothing wrong. Just out of curiousity, what do you guys think would be the symptom of shaving too much?

[Marc Bixen]

Porsche manual says..... "The 87-89 G50 flywheel can not/ must not be resurfaced. "PERIOD!

[porschyard]

Originally Posted by Marc Bixen

Porsche manual says..... "The 87-89 G50 flywheel can not/ must not be resurfaced. "PERIOD!

And we all know PORSCHE is never wrong

I have had dozens and dozens of G50 flywheels resurfaced over the years and never had a problem. As John Walker pointed out this a step flywheel and must be machined the same amount on the pressure plate step that the friction surface is machined.

IMO the OP's clutch disengagement problem is not due to the flywheel being resurfaced.

[KTL]

So you're getting clutch movement via the master and slave. But I agree that it could be air in the system. The hydraulic system moves very little fluid and the placement of the master cylinder relative to the slave cylinder does not lend itself to air bubbles always working their way out. The master is lower than the slave since the master is on the floor in the pedals and the slave is higher up up on top of the trans. So air bubbles tend to not work their way out if you're not forcefully bleeding the system.

You could try removing the slave from the top of the trans and hanging it down below the floor of the car. Then bleed it the same way with your vacuum bleeder. This will help the air bubbles find their way down the line via the fluid pushing them along and not getting hung up in a high spot along the way? Worth a try......

Did you mess with the linkage in the pedals at all? I found that adjusting the positioning of the pedal linkage (the linkage that deals with the assist/return spring) did not produce the desired result I was looking for, which was a lower clutch engagement point. The G50 pedal typically has an engagement point near the very end of the clutch pedal travel. So I fiddled with the linkage and it made matters worse in that I couldn't get the clutch to disengage and thus I couldn't select gears. I was using the Bentley manual at the time and it actually has some good information in it about the G50 pedal linkage. It provides a better diagram of the linkage where there's an eccentric bolt and has an explanation that's clearer than the factory Porsche manual.

Speaking of the factory manual, the directive in the Porsche manual that forbids the flywheel resurfacing is based upon the tall rubber damper of the original clutch disc. The reason being is that they foresee the top of the rubber damper brought closer to the "roof" of the clutch housing where the release bearing is hanging low, potentially causing interference.

However, when you do away with the tall rubber damper by installing a spring-centered disc, which is typically at least a couple inches shorter in height than the rubber unit, the issue of clutch housing interference is eliminated.

So you can indeed resurface the '87-'89 flywheel. Like John said you need to do a double cut to maintain the same placement of the clutch housing relative to the flywheel friction surface and use a spring center disc.

First picture below is the page from the '84-'87 Tech Spec book about the '87 flywheel. Second picture is a page from the factory 84'-'89 Carrera addendum to the '72-'83 911 factory manual (see yellow highlighted box)

I've personally seen resurfaced G50 flywheels work in a couple of cars I had my hands on (mine and a couple of local friends) and we had no issues. It's also something that's been mentioned here on the forum for a long time and others have had success with it as well. Edit..... porschyard beat me to it.

I'll send you a PM and I can get you the portion of the factory manual that covers the G50 clutch control- pedals, master cylinder, bleeding hydraulic system, etc.

[Dan J]

I also don't think your problem is the flywheel Though I've been wrong many times
I was wondering which cross shaft set up you have? I have seen people drop some needles
out of the bearings and cause this condition.
While you have it out you should also measure the thickness of the disc as I have seen this wrong in Sachs kits as well
PS: I don't care what Porsche says either

[lite75]

^^^ pressure bleed^^^

[Eric D.]

Could the fingers for the clutch fork be on top of the throw out bearing instead of in the grove of the bearing?

[Mr.Ebola]

It looks like the fork is in the right place. I can physically see the pressure plate springs pull off the clutch via the inspection holes on the driver side of the car. A buddy of mine reffered his friend to come over and inspect the car who has been working as a porsche tech for 30 plus years and told me the clutch is working properly and has advised me to try filling it with swepco fluid. Says maybe the syncros are not lining up correctly. I hope thats the issue. Im going to give this a try before pulling everything out, double checking my work, and sending the transmission to a gear shop. Im almost tempted to putting the old clutch, pressure plate, and bearing in to see if it works again.

And thanks KTL for the info and the documents. Im going to try that first. Really apreciate you all for taking the time to shed knowledge.

[john walker's workshop]

Swepco won't fix anything. Just pressure bleed it.

[Techno Duck]

I agree with John, try bleeding again.

Whats the condition of the rubber hose that runs between the clutch master and slave, is it bulging? The rubber swells over time and also can bulge externally... you will have a less than stellar pedal feel if this is happening.

The clutch pedal stop Cory is talking about is adjusted with a sliding bracket that is mounted on the wooden floor board / pedal box cover.