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MG MGB Technical - Clutch rattle?

Fitted a new clutch 5/6 years ago when rebuilding the engine, cannot remember what make it was. Only done 5/6000 miles since fitting. Now after a run when the engine is warmed up on tickover It rattles quite noisily but once the clutch pedal is depressed it goes, I assume it coming from the clutch maybe poor quality but, more worried that it could be end float of the crankshaft.
Would welcome recommended makes of replacement clutch. Thanks Trev
Trevor Harvey

With it rattling see if pushing the release arm backwards as if you were trying to disengage the clutch. Does the release arm move back a bit and stops it. Can you feel anything nudging it forwards again? If you let go of the release arm does it come forwards a bit and start rattling again? If so could be crankshaft thrust washer wear, which might also be visible at the crank pulley while someone operates and release the clutch.

Otherwise there should be a spring in the clutch slave continually trying to push the piston out, which is designed to take up wear at that end as it occurs. Maybe that's not doing its stuff.

Or wear between the release bearing and the release arm, or the graphite ring has worn down. The latter wouldn't normally happen that quickly but there have been cases where the graphite ring breaks up.

Clutches are tricky. AP or Borg & Beck are the usual choices but they have had a very close manufacturing relationship. Borg & Beck have been OK for me so far on three cars, but elsewhere an AP had the release ring come away from the diaphragm springs after just a few days. There is another beginning with Q (I think!), can't get Qualcast out of my mind but it isn't that. Years ago opinion seemed to be to avoid that one.

The other thing is to leave it until it breaks!
paulh4

Your probably thinking of Quinton Hazell Paul.
Andy Robinson

Depends on what the rattle sounds like which is almost impossible to diagnose without hearing it-
The noise also sounds like it could be coming from a gearbox low in lubricant that will rattle hot and stop rattling with the clutch depressed
Does the rattle go away as soon as the clutch is pushed down just a little or isit when it's right down like when changing gears
Light tingly rattle or more of a deep rumbly rattle
William Revit

QH - that's it, came to me just after I had switched the computer off.
paulh4

I fitted a 5-bearing MGB engine into my MGA a couple of years ago and it has recently developed a rattle from the transmission, which is silenced when I depress the clutch pedal.
So I presume it is to do with either the clutch release bearing or possibly the springs on the clutch cover which may have become a little loose in their mountings.

So it is only present (or audible) when you are running the engine in neutral.

I am not unduly worried about it although I will have a look to see if the clutch lever assembly looks ok, just to make sure nothing is loose.

Cheers
Colyn
Colyn Firth

I had a similar sort of noise a couple of months ago which turned out to be the clutch thrust bearing pivots needing a drop of oil. Tricky with engine in getting inside the clutch housing but so far so good. Put how i did it and some pics on my blog at https://mgb.tips/2020/07/01/oiling-thrust-bearing-pivots-in-situ/
steve livesley

Just over from the midget & Sprite threads.
Seeing the mention of Quinton-Hazell Diaphragm Clutches. The clutch cover pressure pads can come adrift. They are held on by a ring inserted from the rear which is then swaged onto the pressure pad. The swaging is not sufficient and the parts part company initially having a tinkling sound but later jamming the clutch. The solution I use is to re-assemble and tack weld the two parts together as for my set up I can only use the QH brand clutch on my Sprite.
Alan
Alan Anstead

This thread was discussed between 10/08/2020 and 13/08/2020

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