Clutch plate stuck in disengaged position?

[jonj55]

'70 SII Coupe:

Started the car after one year of sitting (started right up! (live in Los Angeles and car is in Florida)), engaged reverse ready to go for a spin, eased clutch all the way out, nothing....

Can put it in any gear. Clutch pedal feels good and firm. Pumped it awhile, tried all gears but letting it out doesn't move the car. Is the friction plate stuck in the open position? Wondering if there is a fix without getting into the housing.

Thanks for any tips.

[christopher storey]

Very strange : it is common for the friction plate to weld itself to the flywheel, but the reverse is very difficult to envisage, because something would have to be holding the pressure plate back against the diaphragm pressure. I would suspect a hydraulic problem , either the master cylinder or slave cylinder pistons seized in the bore , or the flexible hose internal bore having collapsed on itself, thus acting as a one way valve

[dal2.0litrefrogeye]

Pop car up in air and with an assistant see if actuator arm goes in and out with clutch pedal movement ??

[JerryL770]

If I was putting a car into long term storage, it would possibly be wise to floor the clutch pedal then jam a block of wood in to hold the pressure plate off the driven plate, to stop them welding together.

[jonj55]

The actuator arm does move in and out when clutch pedal pushed.

First thing today I pumped some new fluid through the system. With it full and bled, disconnected the actuator arm from the fork that moves the release bearing, loosened the nut on it and screwed in the flange to shorten it, which should push the friction plate closer to the drive plate. This worked for a couple minutes, enough to go around the block with some clutch slippage. But didn’t last long and again it was back to no clutch engagement when in gear and the pedal all the way out. ended up pushing her home.

He flange is bottomed out on the rod so it can’t be shortened further.

I'm wondering if the release bearing is so worn that it won't push far enough to let the friction plate engage.

On to tomorrow!

[christopher storey]

The release bearing operates to disengage the clutch, not to engage it . It does not push the pressure plate and friction plate closer to the flywheel . Worn release bearing results in the clutch dragging , not slipping. I think the adjustment to the limit stop which you have made will have resulted ( if you have reconnected the slave cylinder ) in the pressure plate being excessively withdrawn even when the pedal is at the top , thus resulting in slippage . The symptoms now are more suggestive of a worn friction plate( possible ) or maladjustment as a result of your altering the stop position ( highly likely ) , and this is particularly so if it was operating normally before you stored the car

[Mich7920]

And the possibility of an oil leak on the flywheel ?

[jonj55]

"loosened the nut on it and screwed in the flange to shorten it, which should push the friction plate closer to the drive plate."

Mich - I would think there would be some kind of noise if there was oil on the driven plate causing it to slip against the surfaces, rather than silence and just free revving with the clutch pedal at top position (all the way out). But I'm not certain about this.

Chris - Yes, I misspoke in the above. The idea in shortening the length of the actuator arm was to allow more travel for the release bearing away from the diaphragm spring by pulling on the clutch fork. Similar to the effect of a spring, which helps retract the actuator arm pull back into the slave cylinder. Mine does not have a spring or a washer-like flange behind the mounting bolt where a spring might have been attached. I'm wondering if it had been there at one time and who knows who mechanic who knows when had reinstalled the slave cylinder without pitting the spring back on.

Doing that thinking perhaps the release bearing was sitting on the diaphragm spring some at top pedal position, not allowing the pressure plate to push on the drive plate enough.

It wasn't really operating normally before, just operating. The clutch would grab at near the top of the pedal.

Wondering if the diaphragm spring could have lost the spring it it's step. Or gaps have become malaligned.

I feel this can only be further diagnosed by getting into the bellhousing, unfortunately.

Thanks for the tips!

Jon

[mgcjag]

Hi Jon.....there is a small hole in the bottom of the bell housing aboug 1in diameter.....you should be able to look in there and see the release bearing and see how it engages.....disconnect the pushrod..from the fork and see how the fork moves the release bearing backwards and forwards......then connect the pushrod and adjust as per the service manual.....its not unusual for the slave cylinder to have been replaced and also the pushrod...there are different length cylinders and pushrods...they need to match.....Steve

[JerryL770]

If you disconnect the pushrod or remove the slave cylinder entirely so that nothing is working on the release arm and the clutch still slips (try starting the engine in 1st gear with plenty space in front - or just bumping it), it would seem either the driven plate is too thin or the spring has collapsed.

[Series1 Stu]

This sounds like classic clutch wear to me. The friction material may have detached from the clutch plate due to the car standing so long. That could account for the relatively low mileage on it.

I think you need to replace the friction plate, pressure plate and thrust bearing to ensure its all good and check you have the right slave cylinder too.

Otherwise you may spend weeks trying to find the precise cause only to realise that the engine needs to come out anyway.

Regards

[madjack4]

Hi the the problem u have is the seals have swollen in the master cylinder blocking the fluid return to reservoir so when u release the clutch its not fully going back to check open the bleed nipple on the slave to release the pressure i think u find it works for a couple of times till pressure builds up again replace seals or better fit a new master cylinder

[jonj55]

MadJack - Yes this seems to be the case.

Update:

Today I again disconnected the slave cylinder actuator arm from the clutch fork, but this time pushed the arm into the slave cylinder by hand as far as it would go and realized it traveled in further than when the pin is in and it's connected to the clutch fork. I bumped the engine as Jerry suggested and it did move the car.

I reconnected it and could drive around the block without clutch slippage, although it only catches at the end of the pedal because the clutch is just worn. The car has 77K original miles and I'm guessing it's never been replaced.

I was just trying to drive it a little as I head back to Los Angeles in a couple weeks. But I need to start planning for engine out and a new clutch, plus slave / master cylinders.

Thanks all for the tips and help!

Jon

[politeperson]

Just out of interest, what number was you car? Looks just like mine that was made in December 1969 and was registered on the West Coast in early 1970.

Mine is 27187

It now lives back in the UK

James

[jonj55]

Looks nice @politeperson,

Mine is 1R27089, not far off.

However, the original color of mine, was light blue. My grandfather had it repainted in the late 70s, preferring the silver, which is a correct XKE color, like yours.

Jon