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MG MGB Technical - New clutch slipping

....under acceleration. Normal while cruising. Is this normal bedding in with a 3.9fi ?
Roger Walker

Do you have a 4-speed O/D ‘box, or 5-speed?
Dave O'Neill 2

slipping is not normal
Is that 3.9 the axle or engine
William Revit

Anything else changed?

Check you can move the push-rod into the slave cylinder a little way at least i.e. the clutch is fully engaged.

I'm assuming '3.9fi' indicates fuel injection hence the engine, needing an appropriately uprated clutch?
paulh4

Definitely not normal. My 3.9 with R380 gearbox never slipped from day one.
Mike Howlett

My 3.9 had a slipping clutch which was new entirely. Mostly noticeable on "take off".
When I removed it, I was amazed to see less than half of the friction material was showing signs of having been I contact with the pressure plate.
When I put a straight edge on the pressure plate, it was concave!!!
It was of "no brand" origin, from a well known V8 supplier!

Allan Reeling

Yes, 3.9Ltr with a LT77 box. I had run perfectly on a normal GTV8 clutch and plate until the bearing gave up.
Allan, I fear it's the same issue but I am about to follow Paul's advice.
Roger Walker

Was the flywheel resurfaced?
Steven Rechter

Steven, Good question - the answer is no and I am kicking myself because I have another. I have also been wondering about cleanliness - there was a lot of dust and oily muck from the last one. Last short test was slipfree but proper run on wednesday will tell.
Roger Walker

If you left the rubbish in there, you're a bit naughty really, also I take it the new pressure plate wasn't cleaned off,-they usually have a protective coating to stop them rusting in the packet-----------IF you're lucky it'll all burn off and all will be well
Was the oil leak repaired
William Revit

William you are spot on - I had a 70m run yesterday without any slipping - looking back, I did see the flywheel and bell-housing with the box off under the car and should have said something (but we have to tread carefully when we eventually have to let others do what we used to do without help on our own). Four score in just a few days but the 3.9 rolls back the years quite convincingly !

Good advice everywhere here - many thanks to all

Roger
Roger Walker

Happy Birthday Roger, i'm not far behind you and fully agree ,nothing better than a blast in the country with a good car to feel good
Have a good one
willy
William Revit

Willy,
Many thanks for your kind message. I hope you too will have a happy one and Many Happy Returns of it.
Roger
Roger Walker

This thread was discussed between 07/09/2020 and 21/09/2020

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