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MG MGB Technical - clutch rust

I have recently fitted a replacement engine in my '75. It had been sitting around for a while and on examining the clutch plate I noticed some rust on the fly wheel and pressure plate. there was still alot of wear left so I rubbed off most of the rust and carried on. Once fitted the clutch would not release so I again I carried on.. thinking the rust was causing the plate to stick and expecting it to wear off when the engine was running and there was more friction. Unfortunatly this hasn't happened and I can't select a gear while running. The next plan is to bump start, and put some stress on the clutch whilst depressing the clutch pedal to try to free it.
Does any one have any advice on this matter, short of removing the engine again.
Thanks in advance.
Dave G
Dave G

Are you sure the hydraulics are working?

Unless the friction plate is actually stuck to the flywheel - which is unlikely, as you have cleaned it up recently - I would have thought there was a problem with the release mechanism.
Dave O'Neill 2

This is getting as bad as on the T series list - too many Dave's. I agree with Dave O, check the hydraulics first to meke sure tha thte clutch release lever is moving at leas a half an inch when the pedal is depressed. If it is, then here is how to procede. Start the car and let it warm up well. Shut the engine off, put the car in first gear, push the clutch pedal down and keep it there, start the car (note it is necessary to have a driving route laied out in advance - preferable something like a circular driveway or somewhere with no traffic to contend with) and drive with hard acceleration/decelleration until the clutch plate breaks free. A variation of this is to put the rear of the car on jack stands and do the same thing using the accellerator and the brake until the clutch disk breaks free (make sure the car is solid ont he jack stands and is not aimed at a wall in case it slips off the stands). Cheers - Dave
David DuBois

Thanks for your advice guys. Ive checked the release lever and it moves about 1/2 inch.
I have questioned my fitting competence and although I checked the friction plate fitting at the time, maybe I fitted it the wrong way round in a moment of madness.
If so would this have the symptoms described ?

Thanks again

Dave G
Dave G

Fitting the friction plate back to front could cause a problem...assuming that it is possible to bolt the pressure plate up with it the wrong way around?

A friend of mine once fitted a new clutch in his Sprite but found it wouldn't disengage. When he took it out again, he found that the manufacturer had assembled the friction plate incorrectly and even though it was fitted 'flywheel side' towards the flywheel, it was offset the wrong way and it jammed solid when the pedal was depressed.

As I said before, I doubt that it is rusted to the flywheel if you have cleaned and refited it recently...unless you've had floods in Surrey, too?

Dave
Dave O'Neill 2

I've now tried to fit the friction plate the wrong way round (on the old removed engine)and Dave O is right it can't easily be done...so thats not the problem.
I rechecked the slave cylinder and release lever movement...apart from getting alot of resistance in the pedal there is bearly 10mm (1/2 inch) movement of the release lever. Could the pressure plate assembly be stiffened due to rust and therefore not releasing ?
All comments appreciated.

Dave G

ps haven't tried the bump starting plan yet !
Dave G

Is the disc sliding on the splines of the input shaft freely?
Tom

Oh yeah. Is the input shaft of the tranny an interference fit in the crank bush? That would make your tranny active no matter if your clutch is releasing or not.
Tom

Thanks Tom
I replaced an 18V engine with an 18V so there should not be any interference with the crank bush.
I've now tried Dave D's method around the block with no success, it's therefore not due to sticky friction plate.
I will now replace the slave cylinder and hope thats the problem.
Dave G

Dave O'Neill 2

You must be a soothsayer.... floods in Surrey today !
Dave G

This thread was discussed between 18/07/2007 and 20/07/2007

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