18 replies to this topic

[Cooperman]

Here is a re-post of my clutch drag fault-finder, I hope it helps:

 

CLUTCH DRAG

 

Clutch drag or failure to disengage is not an uncommon problem with the Mini.

There are several possible causes as follows:

1. HYDRAULIC SYSTEM

1. Wear in the pedal spindle or failure of the pedal to master cylinder clevis pin.
2. Failure of seals in the clutch master cylinder.
3. ‘Ballooning’ of flexible hose due to internal hose degradation or damage
4. Air in system due to inadequate bleeding
5. Failure of slave cylinder seals

 

1. MECHANICAL SYSTEM – WITHDRAWAL MECHANISM

1. Wear in top clevis pin
2. Wear in lower clevis pin
3. Bent arm
4. Worn or broken ball at lower end of arm where it engages into plunger.
5. Wear in plunger ball seat.
6. Incorrect setting of overthrow stop nuts
7. Incorrect setting of adjusting screw (pre-Verto)
8. Corrosion between plunger and clutch cover due to lack of lubrication.
9. Thrust bearing failure – accompanied by a lot of noise.

 

1. THE CLUTCH ASSEMBLY

1. Failure of clutch diaphragm spring due to fatigue or distortion
2. Centre plate hub not sliding on primary gear splines.
3. Clutch plate surface de-laminating or breaking up
4. Distorted clutch plate.
5. If fitted, clutch plate shock springs broken and causing a ‘jam’.
6. Primary gear not rotating freely on crankshaft due to either  i)  Insufficient primary gear end float,  ii)  Primary gear bushes seizing on crankshaft, or  iii) Primary gear bushes breaking up

[Austin mini 30]

Here is a re-post of my clutch drag fault-finder, I hope it helps:
 

CLUTCH DRAG

 

Clutch drag or failure to disengage is not an uncommon problem with the Mini.
There are several possible causes as follows:

• HYDRAULIC SYSTEM

• Wear in the pedal spindle or failure of the pedal to master cylinder clevis pin.
• Failure of seals in the clutch master cylinder.
• ‘Ballooning’ of flexible hose due to internal hose degradation or damage
• Air in system due to inadequate bleeding
• Failure of slave cylinder seals

 

• MECHANICAL SYSTEM – WITHDRAWAL MECHANISM

• Wear in top clevis pin
• Wear in lower clevis pin
• Bent arm
• Worn or broken ball at lower end of arm where it engages into plunger.
• Wear in plunger ball seat.
• Incorrect setting of overthrow stop nuts
• Incorrect setting of adjusting screw (pre-Verto)
• Corrosion between plunger and clutch cover due to lack of lubrication.
• Thrust bearing failure – accompanied by a lot of noise.

 

• THE CLUTCH ASSEMBLY

• Failure of clutch diaphragm spring due to fatigue or distortion
• Centre plate hub not sliding on primary gear splines.
• Clutch plate surface de-laminating or breaking up
• Distorted clutch plate.
• If fitted, clutch plate shock springs broken and causing a ‘jam’.
• Primary gear not rotating freely on crankshaft due to either  i)  Insufficient primary gear end float,  ii)  Primary gear bushes seizing on crankshaft, or  iii) Primary gear bushes breaking up

That is absolutely fantastic!!!! Thanks so much for that! That helps a lot

[Austin mini 30]

new thrust bearing in, and i went to set the throwout nut adjustment to 6.5mm. but the plunger body itself is sticking out a mile!! why is this?

[Cooperman]

The only time I've had that problem was when I fitted a lightweight after-market flywheel. It was new and the taper was incorrectly machined so that the flywheel did not go fully onto the crank tapered end. Sent it back from whence it came and got a full refund.

The other reasons the plunger could sit too far out would be a release bearing not fully seated or clutch diaphragm mis-aligned (can't think how though).