10” clutch on 67 XKE 4.2

Of the three parts supply companies I checked they say a 67 XKE 4.2 has a 9.5” clutch and the 3.8 has a 10”. What is there now is a 10” with several fingers on the pressure plate as picture shows.


In a description on Terry’s website part number HK5229BB, it says

“as a special ordered item Jaguar in would still fit the 10” clutch to later cars, mainly for competition use”.

I’m waiting on Terry’s to get back to me.
Does anyone know the solution without having to buy a new flywheel?

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Hal:

I believe your 10" clutch pressure plate is a Laycock diaphragm unit as fitted to earlier 4.2’s - the 3.8’s had the 10" coil spring style pressure plate and later 4.2’s got the 9.5" diaphragm clutch (depending on build date). Have a look at this thread for some background info + a bit more on the subject - it includes a good summary by @davidxk regarding clutch fitment by model. Suggest you check your flywheel to see if it’s drilled for both 10" and 9.5" clutches:
Have a read: Clutch: replacement problem

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IF you have the correct flywheel for a '67, it WILL be drilled for a 9.5" clutch. It MAY be drilled for a 10" as well. In any case, if you do NOT have the correct holes for the clutch you want to use, take the flywheel and new clutch to any machine shop, and they can easily, and inexpensively, drill it to fit the new clutch.

A diaphraghm clutch is always the better choice…

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Thank you for your response’s. My flywheel is at the machine shop, I’ll check that out.
Thank you

That’s news to me Ray the Diaphram clutches where notorious years ago for failing as the baskets would give up
I switched mine to a Borg and Beck

This should lite it up Lol

Do you believe there have never been poorly manufactured spring clutches??? As a matter of fact, I know several people on this forum who have installed defective spring clutches in just the last few years. So, not sure what point your’e making. If you buy a defective product, it will likely fail prematurely. Buy a good quality product, and it likely won’t. I stand by my statement. A diaphragm clutch is always the better choice. And don’t buy defective parts.

Your picture shows a diaphragm clutch.

The earlier 10" clutch was a spring clutch.

I wasn’t aware that there was a 10" diaphragm clutch fitted to 4.2s.

Regardless, the diaphragm design is a lot better, and is stronger.

If you can get a direct like for like replacement for what you have I would use it. If not, get your flywheel drilled for the 9.5" diaphragm clutch and fit one.

Not necessarily, according to the 3.8 Service Manual later cars (3.8) had a diafragm clutch, although my '64 3.8 has a spring clutch, not sure if its the original though.

Mine '62 came to me with a spring clutch and whilst it was all apart I had the flywheel machined and drilled for a 9 1/2" spring type clutch. I find the new clutch more progressive than the old spring 10" - which itself was a low mileage unit when I pulled it out.

9 1/2" diaphragm - not spring.

Yes, I was generalizing a bit there. For clarification, this is all summed up rather well in @davidxk’s post as I linked to above. Here’s what he says in fuller details for those who may not have read it.

[quote=“davidxk, post:6, topic:390959”]
This thread may benefit from a little clarification (or confusion if I get it wrong :grinning:) concerning the clutches fitted to E-Types.

The first 3.8L E-Types were fitted with a 10" Borg&Beck Coil Spring Clutch Pressure Plate.
In Feb 1964 (i.e. still 3.8L cars), production switched to a 10" Laycock Diaphragm Spring Clutch Pressure Plate. The 10" Laycock Diaphragm Clutch continued well into the 4.2L cars. In June 1967 production switched to a 9-1/2" Borg&Beck Diaphragm Spring Clutch Pressure Plate.

So, the original poster’s 10" Laycock Diaphragm Spring clutch was standard fitment to his March 1965 car. Nothing odd about it at all. The 9.5" clutched weren’t introduced for 2 more years.
[/quote]

In that post from May 2020 David mentions the 10" Laycock diaphragm clutch is “no longer available” so the choice for the OP is either a 10" coil spring clutch or the 9.5" diaphragm clutch - the latter is what the factory used from mid-1967 until the end of E-Type production although the Series III V12 has a 10.5" diaphragm unit. Good luck with your project, Hal. :slightly_smiling_face:

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Somewhere, out of some jeep or forklift or small mechanical equipment, there has to be a clutch cover that will work.

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Thats very interesting, explains why my Jan '64 3.8 still has a coil spring clutch. Amazing what you learn on this forum.

And one important point to mention in this context: Every clutch pressure plate had a different carbon throwout bearing (TOB) to account for the different height (flywheel surface to pressure plate pad for the TOB) of the pressure plate. You CANNOT mix and match them. You need a matched set of Pressure Plate, Driven Plate, and Throwout Bearing.

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881824, my June 64 OTS has one.

Mine is 861460, so seems they didn’t all change to diaphragm in Feb '64.

My 65 early 4.2 (30148) with a build date of Oct 64 has the coil springs and 10" disc.

Rick OBrien

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Wow, that’s interesting, seems like in true Jaguar fashion they first used up existing stocks, or didn’t get enough new ones, before implementing the change.

I think the last time I was looking for a 9-1/2 inch clutch cover I found a 1960-70 six cylinder Ford application that used one?

I am blessed with a local clutch rebuilder that can put together a disc and pressure plate for virtually any combination to virtually any specification. The long-time owner, who recently passed away, was one of the better oval track drivers of the 1960-70’s.

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What end result are you seeking? I’m sure I’ve got a couple of 9-1/2 clutch covers laying around. Free for the shipping cost, if you want one.