clutch not working when enginge is running

[jhjacobs]

Maybe the new clutch kit need to be driven some miles before working properly..?

No. It still sounds like the clutch is not getting fully disengaged. The only differences with the engine running and stopped are that the throughout bearing is spinning when the clutch is pushed and the transmission input shaft is also spinning. Even a brand new clutch should completely disengage on the first release. I am beginning to wonder if your clutch arm pivot ball pin is worn down. I've never had to deal with such a thing and don't know if it can be shimmed our not.

In my years of changing clutches I have, on several occasions, run into after-market pressure plates that just don't work. Basically they just don't get the contact arms set to the right depth for the throwout bearing to push them in enough to release. I've also run into cracked pressure plate contact arms (even brand new) but this generally results in noisy operation. Are you using a BMW clutch and pressure plate? The right part numbers? I guess a throw-out bearing being too short could be in this category as well.

Also, please make sure your slave cylinder is fully in place and the snap ring in locked correctly. I know this can be tricky to get right since this part picks of lots of road grime. If the slave was not seated by as little as the thickness of the snap ring you could experience what you describe.

One simple test for you: grab the clutch release arm with your hand and try to move it in the direction of normal travel. It should not be loose or rattle (very much anyway).

There is an adjustment point on the clutch system on the linkage between the peddle and the master cylinder. You should have less than about 0.5cm peddle travel before master starts to engage. Even though you have done this, I would go ahead and re-bled the system. The engine does not need to be running for this.

The last thing I will mention is the master cylinder may be going bad. When hydraulic master fail they usually have a slow leak-back like a bad brake master. This the clutch hydraulic use a single stage cylinder it does not seem very likely this is your problem.

 

[jhjacobs]

Maybe the new clutch kit need to be driven some miles before working properly..?

No. It still sounds like the clutch is not getting fully disengaged. The only differences with the engine running and stopped are that the throughout bearing is spinning when the clutch is pushed and the transmission input shaft is also spinning. Even a brand new clutch should completely disengage on the first release. I am beginning to wonder if your clutch arm pivot ball pin is worn down. I've never had to deal with such a thing and don't know if it can be shimmed our not.

In my years of changing clutches I have, on several occasions, run into after-market pressure plates that just don't work. Basically they just don't get the contact arms set to the right depth for the throwout bearing to push them in enough to release. I've also run into cracked pressure plate contact arms (even brand new) but this generally results in noisy operation. Are you using a BMW clutch and pressure plate? The right part numbers? I guess a throw-out bearing being too short could be in this category as well.

Also, please make sure your slave cylinder is fully in place and the snap ring in locked correctly. I know this can be tricky to get right since this part picks of lots of road grime. If the slave was not seated by as little as the thickness of the snap ring you could experience what you describe.

One simple test for you: grab the clutch release arm with your hand and try to move it in the direction of normal travel. It should not be loose or rattle (very much anyway).

There is an adjustment point on the clutch system on the linkage between the peddle and the master cylinder. You should have less than about 0.5cm peddle travel before master starts to engage. Even though you have done this, I would go ahead and re-bled the system. The engine does not need to be running for this.

The last thing I will mention is the master cylinder may be going bad. When hydraulic master fail they usually have a slow leak-back like a bad brake master. This the clutch hydraulic use a single stage cylinder it does not seem very likely this is your problem.

 

[eltonjohan]

Yesterday after spending another weekend in the garage trying to find out whats wrong I decided to leave the car to a guy that work with old cars. Since I so far failed in finding the problem it might take the whole summer before I eventually can fix it and drive the car. At the moment I don't really have time to spend all nights and weekends in the garage so I hope this was the right decision...
I will report what he will find in this matter. The first thing he asked was if the bearing from the fly wheel was ok.

 

[eltonjohan]

Yesterday after spending another weekend in the garage trying to find out whats wrong I decided to leave the car to a guy that work with old cars. Since I so far failed in finding the problem it might take the whole summer before I eventually can fix it and drive the car. At the moment I don't really have time to spend all nights and weekends in the garage so I hope this was the right decision...
I will report what he will find in this matter. The first thing he asked was if the bearing from the fly wheel was ok.

 

[gwittman]

The pilot bearing is the thing I was going to ask about. It has not been mentioned until the last post.

 

[gwittman]

The pilot bearing is the thing I was going to ask about. It has not been mentioned until the last post.

 

[eltonjohan]

It sounds quite possible that the pilot bearing is the cause of the problem.

 

[eltonjohan]

It sounds quite possible that the pilot bearing is the cause of the problem.

 

[jhjacobs]

The pilot bearing would not be a likely source of the described problem. When the pilot is bad is will make noise when the clutch is pushed and/or it will cause chattering when the clutch is engaged under load. Even a very bad pilot bearing is often not noticed until dissembled. On our BMWs the input shaft bearing on the transmission is the most likely to fail since it sees considerable load and if the main bearings start to wear it will see even more stress from crankshaft vibration, which reminds me that I need to change mine soon. Once into it, I will change rear seal, the hardy disk, center support bearing, universal, pilot, throwout, clutch and pressure plate. Shucks, I might as well pull the engine too and rebuild it. This would be a great time to do the AC conversion, firewall insulation, repaint the engine bay, move the battery to the trunk,... damned pilot bearing! :roll:

It sounds like the input shaft is still spinning if you get gear gnash putting it in gear with the clutch pushed and car is not moving. Reverse is more sensitive to a spinning input shaft. It seem to me that there is still something in the path from the pedal to the throughout bearing or possibly the pressure plate. I was also wondering if the clutch disk is too thick or if it has some raised spots on it. A more detailed description of the problem and when it happens would be helpful.

 

[jhjacobs]

The pilot bearing would not be a likely source of the described problem. When the pilot is bad is will make noise when the clutch is pushed and/or it will cause chattering when the clutch is engaged under load. Even a very bad pilot bearing is often not noticed until dissembled. On our BMWs the input shaft bearing on the transmission is the most likely to fail since it sees considerable load and if the main bearings start to wear it will see even more stress from crankshaft vibration, which reminds me that I need to change mine soon. Once into it, I will change rear seal, the hardy disk, center support bearing, universal, pilot, throwout, clutch and pressure plate. Shucks, I might as well pull the engine too and rebuild it. This would be a great time to do the AC conversion, firewall insulation, repaint the engine bay, move the battery to the trunk,... damned pilot bearing! :roll:

It sounds like the input shaft is still spinning if you get gear gnash putting it in gear with the clutch pushed and car is not moving. Reverse is more sensitive to a spinning input shaft. It seem to me that there is still something in the path from the pedal to the throughout bearing or possibly the pressure plate. I was also wondering if the clutch disk is too thick or if it has some raised spots on it. A more detailed description of the problem and when it happens would be helpful.

 

[eltonjohan]

haha! The pilot bearing will make you go bankrupt!

It is possible to put in the forward gears, but not the reverse.
Though, if I turn the engine off I can put in reverse and then start the engine and use it.

 

[eltonjohan]

haha! The pilot bearing will make you go bankrupt!

It is possible to put in the forward gears, but not the reverse.
Though, if I turn the engine off I can put in reverse and then start the engine and use it.