40 replies to this topic

[The Matt]

Sooooo, I've pulled my FUBAR flywheel off now. It's all looking as it should under there to be honest. I've got about 0.005" of endfloat on the primary gear. When I grab the primary gear, it does rotate on the crank tail, but it does feel a little 'sticky'. I mean, I can turn it with my finger and thumb, but I don't know how much resistance there should be and if it does infact feel 'gummed up' or not.

One thing I have noticed though, I have one of these and don't know if I should! I know that the Minispares site says that it's fitted to verto clutches, I'm just wondering if that's stopping the clutch from fully disengaging? Perhaps this is the cause of my problems? It's either this thing or it's the primary gear pinching up on the crank tail, in which case I'll need to get some machine work done, or I'll go for one of these fully floating bushes!

Help plizz!

[Sprocket]

Check that the flywheel is not pulling up against the 'C' washer, if the crank has had the taper re ground, this is a posability

Other than the wear in the other parts, I dont know what else it could be

[The Matt]

I will check for that tonight Sprocket. Though it's not had the taper reground, so I don't think that it could be that. I reckon it's gotta be the primary gear. I might pull the flywheel off one of my spare engines that I know was disengaging correctly and see how free the primary gear is in comparison to this one.

It's gotta be the primary gear. It's got enough endfloat but it must be getting 'sticky' on the crank when the crank's spinning

[mini_turbo_pete]

To me it sounds like the backplate has been machined and too much taken off of it. where the 3 stubs stick out on the backplate people have them machined down as it helps grip the clutch better, if too much has been taken off it has this effect where the clutch won't totally disengage.

Try putting a flat washer between the spring staps and the backplate

[The Matt]

I've tried that one too. It's definitely not the mechanism or the hydraulics of the clutch. When the GF presses the clutch pedal inside the car, I can put my finger on the clutch plate (through the starter motor aperture) and move it. So mechanically the clutch assembly is set up correctly. It's got to be the primary gear sticking on the crank/primary gear bushes IMO.

Cheers for the reply anyway

[mk=john]

Also, you can try checking the play at the clutch pedal clevis pin. It may have worn. As for the stop bolt, I adjusted mine to 0.006" (about 0.2mm) and it worked better. The 0.5mm stated is of course the factory spec, but as long as there is a small gap between the release bearing and release plate on the diaphram you should be fine.

[The Matt]

Yeah, it was pretty badly worn to be honest. So was the pedal, it had an oval hole instead of a round one!

But alas, they've already been sorted so they're out of the frame. I am still convinced it's the primary gear, so I'm gonna get out in the garage tonight and check it over again.

[mk=john]

Cool
I forgot to grease the splines on my Mk1 cooper when I did a clutch job, but there was probably a slither of grease left over from the previous clutch plate.

The clutch set up on minis is defo a weak part of the design, esp the pre-verto type where play alone can cause clutch drag. I soppose there isn;t much left to check except hydraulics?

Have you also checked the slave cylinder clutch hose if if is bulging when the clutch is pressed? The rubber ones can do this esp if the engine get hot.

[mini_turbo_pete]

Have you checked the crank end float? run the engine get someone to press and release the clutch and watch the bottom pully to see if it moves side to side.

[The Matt]

Aiii, checked it all now.

Most of the whole clutch system is now new, so it's been a process of elimination, but it's also meant that the pedal feels better than ever.

It's now got new:

Flywheel,
Clutch plate,
Pressure plate,
Diaphragm,
release bearing,
release bearing carrier/plunger,
slave cylinder,
flexi-hose (goodridge type),
M/C rubbers,
pedal,
pedal clevis pin,
clutch lever,
clutch lever clevis pin,
pushrod clevis pin,
return spring



Now, my wallet's broken!!!

[The Matt]

A quick note to complete the thread.

The issue seems to have been the primary gear. There were a few things I noticed...

Though there was enough endlfoat, there was a high spot on the retaining ring.

The rear face (flywheel end) of the primary gear was a little gummed up.

The front bush (block end) was also a little gummed up.

A combination of flatting off the high point (corrosion) on the retaining ring, cleaning up the primary gear bushes, lubricating and generally cleaning up and checking things has cured it. For now!

Ultimately though, I am going to strip it back down and fit a fully floating front bush to the primary gear (available from Minispares).

Learnt a LOT about mini clutches and their problems though! May even write an FAQ on troubleshooting it all one day!

Clutch is now a light as a feather (even on the orange diaphragm) and works a treat!

I can go backwards and forwards now!