Bill99

I was driving my Porsche 996 Carrera 4 Convertible and noticed some issues. After stopping for a short time, I started the car and while the engine would rev and sounded normal, I found that I could not move. The clutch felt normal and the shifter would engage into all slots with or without using the clutch. After investigating a little I found that the shifter cables were properly attached to the transmission, the brake/clutch fluid was normal and no leaks were evident. When moving the shift lever, I could hear the transmission shifting. Before I take the transmission out of the car to investigate the release bearing, clutch disk, etc. Can anyone think of anything else that might be easier to fix?

Brian_C

I suspect the engine was off when you were able to switch between gears. If I had to guess I would say the clutch slave cylinder failed - it’s not engaging the clutch fork.

Bill99

Actually when I was able to switch between gears the engine can be on or off. I'll see what I can find on the slave cylinder and I did read somewhere in the past few days that it does fail and I saw repair kits. Not sure whether it is worth repairing or new if that is the issue. I want to get this back on the road so I can get back to my 1990 928 S4 restoration.

Thanks for the response. It has been tough to get some advise.

Bill

Brian_C

Ok. I’m completely befuddled you’re able to switch gears with no clutch and engine running. Unless there is zero material remaining on the friction disk???

Bill99

I know it. I can't figure it out. If the engine is running I can switch the gears. Without the engine running I can hear the gears move. So I can only think that the disk has no material or the fork is maybe broken and so pushing the pedal does nothing because it is not engaging the disk. I will look at the clutch slave cylinder tomorrow to see if that is visibly leaking a also have someone push the clutch pedal to see / feel if the piston is moving. In 2005 PO replaced clutch (burned by neighbor), replaced transaxle, replace rear crankcase seal. A few more looks tomorrow. As a last resort I will just drop the trans and engine and do a full restore on a lot of pieces.

I certainly will let you know what I find.

Brian_C

If the clutch fork, slave cylinder, or any other mechanism that engages the pressure plate is broken then the pressure plate won’t disengage the friction plate. And if the pressure plate cannot do it’s job then the friction disk will be permanently mated to the flywheel. And If there is any material left on the friction disk you shouldn’t be able to switch gears with engine running. If the logic is sound then it’s most likely the friction disk has lost all material and the transmission input shaft will not rotate which will allow you to change gears regardless if engine is running or not.

Non certified and not a professional by any means. But will be very curious to learn what you eventually discover. Good luck!

Bill99

So So So Sorry ! I checked and I cannot put the car into gear while running without the clutch.

Bill

De Jeeper

Then is failed hydraulics. Either the master, slave or a fluid leak. I guess there could also be a broken fork or pivot but i would figure that would make some noise as the parts would be bouncing around.

Bill99

I see no fluid leaks so I will start by changing out the slave, and possibly the master.

Thanks again

Brian_C

Since you’re unable to get car into gear with engine running I think you can rule out the friction disk - though it may be time.

I’m reverting back to a failed slave cylinder. I bet the piston grenaded. Hopefully you’re able to remove it with the rubber sleeve still attached. Otherwise component bits will be floating around in the bell housing.

I had no leakage from my slave when I recently replaced the clutch and DMF. But, there were signs something was failing based on the pedal feel. I removed the slave when tranny was still hooked up and all the slave components inside the bell housing just fell off into the bell housing when I removed it. The tranny HAD to come out at that point.