9 replies to this topic

[Bearddude]

Hi,
I recently bought a Morris mini van which had been restored 30 years ago and had almost no mileage on the clock since. I believe it hadn’t run at all in many years, although all components appear to have had little to no use since the restoration. The mechanics have got the engine running well but are having serious problems with the gears. It won’t engage gear with the engine running (it will engage all gears with engine off). If you engage first and start the car it creeps with the clutch down. Today they changed the entire clutch assembly, but the problems remain. I can sense that the mechanics are struggling with where to go next. Any suggestions please? It’s a 1275 engine and Cooper S gearbox.

[nicklouse]

Sounds like a failed/ing seal or worn pivot parts.

[weef]

I take you mean by the entire clutch assembly it was the mechanical parts only ?. Adjustments will have taken out any "slop" in the linkages so maybe the hydraulics system needs attention. If the clutch is dragging then there cannot be enough clearance with the clutch pedal fully depressed. Ensure the pedal travel is not restricted then check the master and slave cylinder, they will also be of an age and therefore in need of maintenance seal and fluid wise..  Inspect, repair or replace then fully bleed the system and see how it goes. 

[floormanager]

Somewhere recently on here I think that the clutch arm should move at least half an inch when depressed.  Check this, slacken off the throwout stops at the bottom, re-set the arm to the correct position, then re-set the throwouts at the bottom.  If they are too far in then it will stop the clutch from being fully depressed.  Presumably, they checked for rusting etc when they had the clutch out? Clutches can stick when not used.

[Bearddude]

Thanks for the responses guys. They’re making progress - it seems to be a combination of changes which together are moving things forward. Clutch arm and ball are new. Minor clutch adjustments have meant that gears can now be engaged with the engine running, although 1st is tight and reverse is crunching. Trying an oil and filter change next. If that doesn’t resolve things completely it looks like a choice between giving the car a good running-in (it hasn’t been driven much in 30 years) to see if things improve or doing some machining on the primary gear to get some more clearance.....

[MiniMadRacer]

Did they shim up the primary gear properly... a factor many ignore which allows the primary gear to slap up and down on the crank (if lose) affecting clutch operation

[floormanager]

Keeps us informed.  Drove mine today after a engine swap (re-built engine, gearbox etc).  Clutch is operational but 1st a little stiff and if you grab reverse quickly you'll hear a clunk.  Going to add some more miles (when it stops snowing and see how it all beds in.  The primary gear was shimmed up as best as I could, so hopefully should be okay.

[Bearddude]

@Floormanager - funnily enough you could be an echo of my situation. After a change of clutch (along with a discovery that whoever put the original clutch in had stripped the threads into the camshaft) and an engine oil change, all gears can now be engaged although 1st is tight and reverse crunches a bit. I received the same advice - put some miles on it and see if it beds in). If not (and if it’s not something I can live with) it’ll be a case of machining a bit off the main gear. This is my first older car in a very long time time and I’d forgotten about these little foibles

[Cooperman]

In case it might prove hard to find, here is my CLUTCH DRAG FAULT FINDER again. 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

[floormanager]

 

In case it might prove hard to find, here is my CLUTCH DRAG FAULT FINDER again. 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

 

My job for the weekend, thank you Pete!