[E-Type] Clutch 9.5" vs 10"

A quick note on the importance of balancing.

When I rebuilt my most recent MGA, I took the FW and PP to a machine shop to be surfaced and balanced. Flywheel first, it needed a very small hole to bring it true. Then, adding the PP required a 20 gram weight to be added proving that at least that mfgr. does NOT balance their pressure plates.

20 grams on a 4 banger would have been felt at just the right rpm range.

Is it my imagination, but donā€™t the teeth look a bit blunt on that flywheel?

My balance shop almost always added weight on PPs.

From my experience the 4.2l Ser 1 and 1.5 flywheels were stamped with the engine number, if you are having problems determining if a 3.8l flywheel has been used on your 67

I think I agree but Iā€™m not sure which 5 year-old post youā€™re taking issue with. Iā€™m sure all 10" clutches of either type would have the same bolt pattern, but I guess youā€™re saying there were no dual-drilled flywheels until 66/67?

Peter the post dated Sep 13 2013,
" The 10" clutch isn`t standard on any 4.2"
If this statement is not yours then apologies.
Mind you! if I had spotted that the post is 5/6 yrs old I would not have posted.
Dual drillings perhaps with the advent of 3.4 MK1 (10"spring) and 2.4 (9 1/2"spring).
Peter B.

Fair enough. I was sloppy and by 10" I meant the coil spring clutch.

In any event, Iā€™m removing a 10" diaphragm pressure plate from my dual-drilled #9537 flywheel, and installing a new 9.5" PP and disc.

Iā€™m still looking for a shop nearby that can balance it without the crankshaft. My regular guy hasnā€™t got the proper flange for it.

Patrick,

When I replaced my clutch a couple of years ago I couldnā€™t find anyone that sold a 10" clutch. XKā€™s Unlimited in San Luis Obispo is quite knowledgeable about Jaguars as he has been in the business for over 40 years and involved in vintage racing almost as long. They say the 9" is superior to the original and in any case is plenty strong to handle the EType torque. Regarding the engine number on the flywheel I didnā€™t look for it so I donā€™t know.

Regards, Leon

Read this whole thread and looking for a reco. Iā€™m converting from Johns 700R4 to a T5 and looking for a 10" PP to take a 10" Ford clutch disc. XKā€™s has both B&B Diaphragm and regular spring PPā€™s. The B&B is almost twice the price. For general street driving is there a compelling reason to get the diaphragm?

Iā€™m doing a T5 setup in mine. A knowledge shop locally found a 9.25" Clutch Disk that has a ford T5 spline - I believe it was designed into a Kubota tractor originally. The question is will the .25" additional surface area really helpā€¦depends on how many burn outs you do maybe?

Hmm. No comment on that. I went with the spring type based on Paul Cā€™s recommendation.

For future reference. 1-1/16"-10 spline, 9-1/2" clutch disc. No Kubota tractor parts requiredā€¦

1 Like

Hum. Thatā€™s much better- wish I would have found this before!

Hi
Just to resurrect this post perhaps someone has similar issues to mine

I have a Dec/jan66/7 4.2 and fitted a new clutch. I am about to install but concerned with the fork position. The pressure plate I took out was deeper than the 9.5 replacement. I am concerned that the splines will not release the plate. Any views on this? Thanks paul

I enclose relevant photos

I donā€™t think either of those pressure plates are right for that Miele washing machine. You need part # 4230750001 for early models, or 4230760561 for post 2005s. As for your E-Type clutch you are right to be wary. There are multiple versions of the graphite clutch release bearing with different offsets between the pivot and the carbon face. Treat the pressure plate and release bearing as a pair - if the height of the pressure plate is different, you need a different release bearing. I donā€™t have the details to hand, but there are several posts in the archives (use the Search facility) that show photos of the differences.

Typically on clutches this size the release bearing needs to move .375" in, once contact with the center of the diaphragm occurs, to release the disc. Given the mechanical advantage of the lever based upon itā€™s lengths each side of the pivot (1.6 to 1) the outer end of the arm needs to move .600 inches more or less to release the disc.

Normal clutch pushrod travel is ~3/4". And, as the disc and throwout wear, the position of the clutch fork can move in EITHER direction. From that photo, you have nowhere NEAR enough travel.

I agree with David that you either have the wrong throwout bearing fitted, or a totally unsuitable pressure plate. You should have the thicker one. If you already HAVE the thicker one, then you need to return that whole clutch pressure plate and disc, and get the correct ones.

yes Ray that is exactly my concern. However both seller (SNG) and manufacturers are adamant I have the correct set.

Not really sure how to proceed now

Remove the gearbox, and take a clear photo of the throwout bearing, from the side, with a ruler or tape measure next to it. People here can confirm you have the thicker throwout.

I can pretty much guarantee that if you put it back in the car like it is, you will be pulling the engine again very soon. I would even suggest you make up a length of brake line long enough to test the clutch actuation using the cars master cylinder, before putting the whole thing back in the car. That is the only way I know to be 100% certain all is working as it should.