Replace spring type clutch with diaphragm type on S1...any experience?

True: they are really only useful for ease of assembly.

Thats music to my ears (eyes)! I did wonder if the dowels were really necessary. I have sent the flywheel for skimming today so can tell the engineers to leave the dowels out.

That said, proper short-shoulder bolts should be used, and not standard ‘threaded all the way up’ ones.

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I would love to use a diaphragm clutch as a replacement. I am just nervous that the bearing won’t release the clutch due to some variance in dimensions somewhere. If I was confident that the complete diaphragm clutch kit (plate/pressure plate/bearing) install and operate without any risks, i would fit it without hesitation.

Whatever kit you buy “should” have the correct TO. It’s worth the check, but I don’t see it as a huge risk.

That too is music to my ears. I think my confidence is unto 98% now to go for the diaphragm!

The one thing I’ll caution is that sometime last year there were reports of bad diaphragm pressure plates that were coming apart and at least one supplier pulled them off the shelves. I think but am not at all certain it was the AP brand. Hopefully someone can confirm or deny my memory on this?

Double, triple check that you have the correct throwout bearing for whatever clutch you use. Install the wrong one that ear to ear grin you have on your face at first start up will rapidly fade of a look of despair. Ask me how I know this, better yet, don’t ask.

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It is possible to check this as soon as the bell & box and fitted onto the engine and before installation into the car. With everything correctly matched the clutch fork will emerge about in the middle of the range of travel allowed by the slot in the bell. Too far back and you have the wrong release bearing, from the spring clutch…

There are an amazing number of carbon clutch release bearings available, so it is a concern. I assume this is for your Ser II car? I think that you can rely on the usual parts supply places to sell you the right one with a new diaphragm pressure plate assembly if you tell them what car you are installing it on. They sell a lot of these packages. As I recall the release bearing for these diaphragm p.p. assemblies is quite thick.

So where were you with this advice 18 years ago when this happened? :laughing:

Seriously that’s good information for anybody to have when they are replacing these things.

True for both clutch types?

Yes. although I’d never fit a coil clutch I believe if a diaphragm release is used with spring clutch the lever emerges too far forward. In both cases the clutch may be adjusted to work initially but the bite point can be in a strange place and 10-15,000 miles later the clutch is probably going to slip or drag as free play is used up. There are other combos, but in general if the mech has scope in each direction you’re golden.

Yes.

Regards,
Ray L.

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Here are the 2 release bearings. Diaphragm on left . Spring on right.

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This is the information I have been waiting for. I really wanted to now how to check before installing the unit to the car. Many thanks Peter

No its a late S1 1966. SNG list diaphragm type again this model in their parts page.

Jaguar’s own parts book for the 1966-launched 2+2 also only shows a diaphragm clutch.

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Forgive this question after all the great responses, but…I can be quite confident of using a diaphragm clutch if it comes as a complete kit, as the release bearing should be the correct one for the supplied PP?

Fingers crossed!

If that’s a question and you buy a name brand 3-part kit, the answer is yes. AP, Luk, Borg & Beck etc…

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