A while back, when we were discussing the clutch pedal sticking problem some of us have experienced, someone (Randall G?) mentioned sticking shift levers, but did not elaborate because it was not a related problem. My shifter likes to hang up in first if I park the car on a slight incline... I have to get the car rolling forward before it will disengage, or really pull it which seems a bit harsh. Is this the sticking shifter mentioned, and if so, any ideas for fixing it? Thanks, Mark.

 

Hi Mark,

Yes, it was me that mentioned a "sticking-in-gear" problem. Other people that have had the problem include D.J. and Dave Edwards of the 993 board. Suppose there are others, but can't remember just now.

Symptoms include sticking in first gear when parked on an incline (like yourself), the car moving forward after starting--even with the clutch fully depressed, and not being able to remove the car easily from gear while decelerating (e.g., coasting/downshifting)--as if the clutch pedal hasn't been depressed at all. D.J. said he also had the problem on upshifts (accelerating), but he apparently had an advanced case.

The cause is binding between the transmission input shaft and clutch disc, as a result of surface corrosion. In both my own and D.J.'s case, our mechanics failed to carry out the below during a clutch job (highlighted text):



When my transmission was removed, my (new!) mechanic also found the bell housing vent and slave cylinder cover missing, which allowed moisture into the bell housing. As a matter of fact, they even found some standing water inside!

Unfortunately, the fix is to remove the transmission, clean up the input shaft, and clean-up or replace the clutch disc. Then, lube/seal components properly during reassembly.

The major downside I can see to leaving this problem uncorrected is (possibly) accelerated wear of the gear synchros. If the clutch is not disengaging fully, the synchros are now breaking the momentum of not just the input shaft, but some portion of the flywheel/engine's momentum, as well.

Best of luck!!

 

oops

 

Mark:

The problems can be caused by several things. Randall has identified one of them. It sounds to me like what you're describing is the clutch disk dragging on the flywheel. When this happens and you punch the clutch pedal, the clutch mechanism (including the hydraulics) isn't allowing the clutch disk to separate from the flywheel completely. It could be a lot of things including hydraulics (this happened to an old car I owned and it was a slave cylinder failure). If you're lucky it will be hydraulics since the work Randall is referring to is not cheap!

Good Luck,

Bill Wagner

 

Hello Mark,

Bill has a very good point above, and boy, did I want to simply replace the slave cylinder when I had this problem. But, my mechanic talked me out of it, based on the symptoms described above. In retrospect, this was a good thing, as it made the eventual repair some $200 cheaper.

Here's an excerpt from an e-mail my mechanic sent me, discouraging me from replacing the slave cylinder:

********************
"If the car is parked on a hill with the front facing up the hill, engine not running, emergency brake off, clutch out and in 1st gear. Without starting the engine, you push in the clutch pedal, the car does not roll down the hill, yet the clutch pedal feels normal. Now, if the throwout
fork were hanging up, it wouldn't keep the fork from going down, but it would keep it from returning and the clutch would slip, not stick. If there were air in the system, you'd have to push the clutch down either multiple times, or it just wouldn't release, which we are getting in this case, but under normal driving conditions there is no such problem, and the slave cylinder has no reference to the loading problem, so it's out of the question also. This leaves us with two possibilities that could possibly hold the car from rolling down the hill..


1) the pressure place face is not following the spring when the pedal is pushed down. Now keep in mind that this is a pull type pressure plate, not
push, and the light springs retaining the face to the housing are all that pull the face back when the pressure is relieved from it, you're not
actually pulling on the face itsself, only the spring. So, the clutch is bound, the pressure plate face is not returning in a symmetrical manner and is cocking in the housing due to a defective light return spring. But under
acceleration, these springs get put under tension, not compression, and they stretch back to their normal position and center the face in the housing.

2)The pilot bearing is possibly holding the mainshaft from turning due to some side loading under decel. But no sounds, or other conditions exist that would otherwise indicate the pilot bearing. This would typically just not release the mainshaft from the flywheel regardless of condition, so this is probably a far fetched condition.

So, the pressure plate is on the stand. But it doesn't have that 2800 rpm vibration that would indicate it being badly damaged yet, though with the stock, extremely heavy, dual mass flywheel, this may absorb that and not give this indicator.

The C2/C4's have a huge hydraulic reservoir that all the brakes, clutch, differentials, etc. bleed off of, and it's constantly being recirculated.
Unless the fluids become contaminated with water for some reason it should still be in fine condition, and bleeding the clutch should not be necessary unless the system is opened for some reason.

I also feel replacing the slave cylinder at this point is a waste of time and money."

******************

Of course, once the transmission was removed, we found the actual cause to be corrosion. Not explicitly described above, but more or less implicit in his diagnosis.

 

Randall and Bill,

Thanks for the response! My car is exhibiting exactly the symptoms Randall's mechanic described above... Great... I suppose I should look at the bright side and consider this an opportunity to replace the dual-mass flywheel with a lightweight and replace the clutch... but big numbers with dollar signs in front flash before my eyes... money I would rather spend on a set of track wheels and tires, and Big Red brakes! I would guess this job is a bit more than I could manage in the carport... although I have done the clutch in both my Toyota truck and a friends VW Vanagon back there. Of course, with the engine already out, I might not be able to resist the urge to convert to 3.8 liter P&Cs, have the valves and guides replaced, and throw in a transaxle overhaul with tighter gears for the good old speed-limited USA! What to do....

Thanks again, Mark.

 

Hey Mark,

If it's any consolation, you should be able to get a full clutch job (parts & labor) somewhere in the $1200-$1500 range. Clutch kit prices have really come down in price since the mid 90's (when a pressure plate alone was over $500). Even a local dealer here was willing to do the job for "only" $1700. I wound up paying $1210 last June, parts, tax and labor, for an outstanding job.

Of course, be real careful with the LWF .... you know, stalling/idle issues, etc. If my car still had a 964 (pre-OBDII) engine, and I wanted a LWF, I would go with Andial's semi-LWF. Yes, not the maximum lightweight effect, but I don't believe they have any idle problems with their set-up. The chip/idle stabilizer fixes seem to be a mixed bag ... works for some people, not for others.

Why I mentioned OBDII engines .... they are known for handling LWFs without any mods. If they have idle issues, it's a problem somewhere else, not with the LWF.

Best of luck!

 

Hi Randall,

I think I have myself convinced that the DIY approach won't be too bad after all... the factory manual has all the details and it honestly looks pretty easy. I just need to decide if I should stick with the 2-mass, or switch to the LWF. I found a source for the factory RS kit, but will investigate the semi-light from Andial. My car is already equipped with an Autothority MAFS, so I should be able to get a tweaked chip and/or idle stab from them to avoid the infamous idle maladies.

Thanks for the help, Mark