Stuck transmission 993

jollymon · 06-20-2012, 06:24 AM

I have a 95 993 cab manual . The car shifts fine when accelerating, however if I engine brake the gears will not disengage when I depress the clutch; unless I blip the throttle. It is much worse when it the engine is cold. I have checked the clutch fingers and the throw out bearing and they appear fine. I replaced the hydraulic fluid and bled the system, replaced the engine mounts and there is no difference. If I come down a hill in 2nd gear, and let the engine control the speed, depress the clutch at the end the car will actually stall. I can "pull" it out of gear but it is far from smooth. If I push the clutch in when the normal driving and don't let the engine slow me down everything works fine. Any help would be greatly appreciated.

initial · 07-06-2012, 05:20 AM

I have a somewhat similar problem. A local indie and racer suggested I just change the fluid to a new good synthetic. If the problem persisted, I should just put up with it and blip the throttle!

If you ever resolve your issue, please share..

Note: I haven't updated my signature, THe 89 911 3.2 is now a 95 C4 Coupe.

CaptainHal · 07-06-2012, 05:49 AM

I did the fluid change to a synthetic and no change. The mechanic wants to just put up with it, I would like to get it right. I am just hitting the wall on trying to chase it down. I don't want to dig into the transmission but that may be the next step.

matt demaria · 07-06-2012, 07:21 AM

It is not a gearbox problem. The clutch is not releasing. If there is no air in the clutch hydraulics, and if the crossshaft bearings are not toasted it sounds as if you need a clutch. A lot cheaper and simpler than going into gearbox.

bazar01 · bazar01's Garage

I agree, the clutch may not be disengaging. I had this problem before. I just double clutch until I found the time to work on it.
I tried to bleed the system, and ended up replacing the slave and master because I lost pressure during the bleeding process. It worked fine after that but the clutch pedal was so heavy then I ended up dropping the engine/trannsmission after driving it for six months and replaced the clutch, PP, resurfaced FW, release and pilot bearings, guide tube and did the cross shaft update with bronze bushings instead of needle bearings, fixed a couple of oil leaks on the breather section.
The joy of owning a old car and all is fine now.

aigel · aigel's Garage

Definitely sounds like a clutch issue, if it occurs in all gears / equal opportunity. I would hold off going through the transmission until you are 100% sure it isn't the clutch.

I am no expert, but I would do some simple testing on a hill of different grade with the engine off to see if the clutch disengages completely in all gears and the car easily rolls under its own gravity.

G

Geary · 07-06-2012, 06:55 PM

Quote:

Originally Posted by initial

.. A local indie and racer suggested I just change the fluid to a new good synthetic. If the problem persisted, I should just put up with it and blip the throttle!

Hmm .. Well, at least it wasn't your mechanic telling you this. You're putting unnecessary wear on synchros and engagement teeth until this probable clutch issue is solved.

TMc993 · 07-06-2012, 07:21 PM

It didn't come from the factory requiring a double clutch, so why would it be okay now? Get a better mechanic.

initial · 07-17-2012, 05:28 AM

I re-read the original posters problem. In his case, the gears are not disengaging. That would sound like the clutch is sticking.

In my case, when I press the clutch in, the gear disengages everytime (RPM
s drop, no engine resistance), but it's hard to push it out of it's gear position at times. If I blip the throttle with the clutch in, it helps, but not always.

Geary · 07-17-2012, 06:00 AM

Well, the OP didn't give enough info or clarity to fully visualize the issue .. which is OK when it's a common problem that someone in the crowd can immediately identify .. but it doesn't seem to be.

"the gears will not disengage" So this means all gears? .. or just 2nd gear as in your example?

".. come down a hill in 2nd gear, and let the engine control the speed, depress the clutch at the end the car will actually stall." At the end? Does this mean when coming to any full stop? .. or just at the bottom of a hill in 2nd gear? Would it do the same thing if you were approaching the stop (at the bottom of a hill) in 1st gear (just for the sake of a test)? When else might you feel resistance to coming out of gear?

With what we know, it still sounds like a clutch or pilot bearing -related problem.