Thread: slipping clutch mystery

I'm afraid that slipping clutch on this vehicle, in my experience, is almost always oil - the drain may be blocked or it has not got there yet but has got to the plate. If I remember rightly, the drain is on the front of the flywheel housing - if oil is coming from the gearbox, it could well get to the clutch plate first.

The only other possibilities I can see is -

pressure buildup in the hydraulic circuit from a faulty or maladjusted master cylinder - this can be checked by momentarily opening the bleed screw - should ooze fluid slowly - if it squirts, there is a pressure buildup. There is a slight possibility that the pressure buildup is due to a a loose bit of lining in the flexible hose acting as a one way valve, but I think this is very unlikely.

or

The clutch driven plate is just plain worn out. I'm afraid the only way this is likely to happen is either a maladjusted master cylinder or more likely, an abusive driver.

John

Or something has happened with the clutch fork pivot pin or pushrod and applying pressure on the pressure plate diaphragm allowing it to slip. As John said usually you would suspect oil contamination or m/c adjustment as the main cause of slippage.

Originally Posted by Bearman

Or something has happened with the clutch fork pivot pin or pushrod and applying pressure on the pressure plate diaphragm allowing it to slip. .......

I have problems seeing how this could happen - the reverse fault (no clutch), yes, but anything that changes the movement of the fork should be accommodated by the slave cylinder. And the loads on the fork pivot and pushrod are pretty high, so it is hard to see what could happen without resulting in failure. Actually, I suppose a sticking piston in the slave cylinder could cause the effect, but again, it is hard to see how this could happen without radically changing the "feel" of the clutch pedal.

One thing that is not very hard to do is to remove the slave cylinder and have a look inside - this is likely to show oil if that is the problem.

John

John

Originally Posted by JDNSW

I have problems seeing how this could happen - the reverse fault (no clutch), yes, but anything that changes the movement of the fork should be accommodated by the slave cylinder. And the loads on the fork pivot and pushrod are pretty high, so it is hard to see what could happen without resulting in failure. Actually, I suppose a sticking piston in the slave cylinder could cause the effect, but again, it is hard to see how this could happen without radically changing the "feel" of the clutch pedal.

One thing that is not very hard to do is to remove the slave cylinder and have a look inside - this is likely to show oil if that is the problem.

John

John

I have seen pivot pins wear that sloppy in the hole in the bellhousing that they have come partly out of the hole and jammed at a slight angle in that position and apply force onto the throwout bearing and as a result onto the pressure plate causing slippage. Oil leakage into the flywheel/bell housing usually shows up pretty quick in the drain hole.

Yeah was planning to bleed and remove slave cylinder to have a look inside for oil etc.

Originally Posted by JDNSW

I have problems seeing how this could happen - the reverse fault (no clutch), yes, but anything that changes the movement of the fork should be accommodated by the slave cylinder. And the loads on the fork pivot and pushrod are pretty high, so it is hard to see what could happen without resulting in failure. Actually, I suppose a sticking piston in the slave cylinder could cause the effect, but again, it is hard to see how this could happen without radically changing the "feel" of the clutch pedal.

One thing that is not very hard to do is to remove the slave cylinder and have a look inside - this is likely to show oil if that is the problem.

John

John

or you have a melted plastic carrier, or you have contamination of the carrier slide, or you have snot stuck in the fast fill port, or you have a twisted flx hose, or you have the wrong pushrod, or yo have a collapsing flex hose, or a partial blockage of the pipe, or contamination on the front of the MC thats stopping it from returning, or you had a normal dty friction late under the HD pressure plate,

or you have a stuck pivot, or you have the wrong piston in the MC or the fast fill vlave isnt assembled properly

Can you elaborate on the normal duty friction plate possibility? Are they thinner than the HD ones?

Steve

I guess it's just a process of elimination!

Originally Posted by Blknight.aus

or you have a melted plastic carrier, or you have contamination of the carrier slide, or you have snot stuck in the fast fill port, or you have a twisted flx hose, or you have the wrong pushrod, or yo have a collapsing flex hose, or a partial blockage of the pipe, or contamination on the front of the MC thats stopping it from returning, or you had a normal dty friction late under the HD pressure plate,

or you have a stuck pivot, or you have the wrong piston in the MC or the fast fill vlave isnt assembled properly