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MG MGB Technical - Shifting/Clutch Problem

Just finished a 130 mile round trip to Rhode Island, mostly at highway speeds, when I got off the highway when I arrived close to home I had great difficulty at shifting to any gear. At one stop I had to shut down the engine to get it into 1st. I checked the clutch fluid when I got home and it was OK, I didn't have any clutch problems before the trip and no whining sounds from the transmission. In fact it shifted very well all the way down to RI, it was just the last 10 miles that were a problem. Any ideas of what my problems could be?
Joe

Sounds like your master or slave cylinder went kaput. You might want to get a volunteer to push the clutch and look under the car to see if there is movement.
J Arthurs

How do I tell if the slave or the clutch master cylinder is defective? I can shift the car a bit. but I really have to work at it, so the system hasn't totally failed yet, it now just very difficult to drive
Joe

As suggested use an assistant to check the slave cylinder for movement. It may have gone bad OR the flex hose that attaches to it may be bad to and is expanding under the pressure instead of directing it to the slave. FWIW my release bearing went out a few years ago, no warning, no noticable symptoms, just pulled up to a traffic light and it wouldn't go into gear. Had to do the whole "pull engine and tranny- replace clutch parts" thing
william fox

Ok, for the clutch slave cylinder, pull the dust cap back a little to see if any of the Castrol/LMA fluid is present in the cap. If so the stuff is easing past the slave seals. rebuild slave cylinder.

For checking the master clutch cylinder (MCC), take the top off the pedal box, feel the underside of the MCC dust cap for wetness indicating a Castrol/LMA fluid leak from the MCC. Sometimes you can feel the stuff dripping down on your left foot when driving.

For checking the clutch hose, inspect that for cracks, see of it seems to expand when the clutch is deprssed.

For checking overall clutch hydraulic operation, with an observer watching the slave on the right side/bottom-front of the tranny, depress the clutch, the slave should move the fork by about 3/4 to inch.

If everything seems ok but the fork movment, try bleeding the clutch hydruialic system. Bleed nipple is located on the slave near wheer the clutch hose attaches.

If the clutch hydraulics appear to function ok, you may need have a clutch replacement to do.

John Long
John Long

the slave should move about 3/4 of an inch. if it does then the hydraulics are ok. be sure the trans if full of oil,if it is low it will cause hard shifting.
steve

I've always seen 1/2" - 5/8" suggested, and that is what both mine do. Don't assume yours is bad if you only see this movement and not 3/4".
Paul Hunt

Sounds like your tranny may be low on fliud and the gears are getting so hot from the low fluid, that they are expanding making it harder to shift.
Bob

This thread was discussed between 30/06/2002 and 06/07/2002

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