QuestionQUESTION: Barrie: I have had my MGB about a year. Prior to my ownership , work was done to the car to make it saleable. but the clutch. I don't know if it is new or not. Master and slave cylinder are " dirty" and probably are original. Rebuilt? I kinda doubt it. But...coming back from an afternoon drive I began to have problems shifting. Gears grinding. in the last 5 miles clutch stopped disengaging altogether. I could feel a judderring in the pedal. I checked the master reservoir and it was low but not empty.
I topped it off and bled the slave. There IS movement in the arm ( not sure if it is moving enough because I didn't measure). But I did notice that the boot on the bellhousing is disintegrating. Could it be that dirt or grease got into the clutch through the arm opening? Could that make the clutch "stick" . Somewhere it was mentioned that driven plate and clutch surface should be cleaned with a volatile cleaner. Could a cleaner be introduced through that arm hole or am I going to have to pull the engine? Any suggestion short of pulling the engine? What do you suspect and what would you recommend? Thanks John
ANSWER: Hi John. The fact that you are losing fluid tells me that either the master or the slave cylinder is weeping, and urgently needs either a new cylinder or new seals. That would cause the symptoms of gears grinding etc. Have a look at the slave cylinder. Is it wet? Is brake/clutch fluid dripping down the pedals onto the floor?
There is probably nothing wrong with the clutch, just the hydraulics.
... and no, the rubber boot is not the cause of your troubles. Just replace it.
If, after you have fixed the above, you still have a problem, get back to me.
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QUESTION: OK. Im Back. And there is still a problem. I have replaced the master cylinder, the flexible hose, and the slave. Bled the system and there is approx 1/2 to 5/8 inch movement in the arm. ( According to the book this is correct) Clutch is still stuck. I'm suspecting I need a new clutch. There is "judder' in foot pedal. Plates are "stuck" together. However, I'm hoping you might have another thought. Pulling the engine is not something I had planned to do just yet.. it would be a shame to pull the engine and NOT do all the other stuff I'd like ( would love to put a 5 speed Ford type nine gearbox in this car... if I could find one I can afford). But then again, maybe it isn't as daunting as I fear.
Any suggestions to try first? John
ANSWER: Hi John. Sounds ominous. Have you inspected the clevis pin that attaches to the clutch actuating lever? Sometimes there is a lot of wear there, and this can result in lost motion.
Judder can be the result of soft rubber mountings underneath the gearbox, or soft or broken mountings at either side of the engine. Lift the engine slightly on a jack to see if the rubbers have split from their metal plates.
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QUESTION: The pads don't appear to be split. The cleavis pin is old but not worn enough to stop the clutch from disengaging. I supported the gearbox with a Jack and tried again. Clutch still engaged. There is a definite vibration in the pedal as it moves in and out. Also I noticed ( and this seems strange) that the idle speed decreases when I push the clutch pedal in. and increases when I take my foot off of it. (Usually with the clutch pedal in and the clutch disengaged, the idle would increase not decrease.)
I'm njot sure how the throw out bearing attaches to the plate but it obviously is not pulling the two apart. (Or does it push them apart?) Anyway, your thoughts on my next step are appreciated EVEN THOUGH I THINK YOU'RE GOING TO TELL ME TO PULL THE ENGINE AND BUY A NEW CLUTCH. Or can you think of another culprit.
AnswerI am afraid you are right. Out she comes. My guess is that the carbon thrust bearing has worn out, or possibly one of the ears has detached itself from the fork.
This parts diagram may help:
http://www.ukmgparts.com/browse.aspx?CID=a06aab03-5ebc-49d9-a937-a6d8adfce6c1&SI
