Clutch model

[Philippe-J.]

I am somewhat confused about the clutch I found in my feb 67 OTS.
It looks like the type for "early cars" as they call it in the workshop manual:

with the violet thrust springs and all.
As a matter of fact, my car being a late series 1, I anticipated a "diaphragm" clutch.
Could the clutch be changed somewhere in the past with an old spare one?
Should I (and can I) go back to the correct type, now that the engine is out?
Thanks for your lights.

PS: as can be seen on the image, some parts (including the cylinder block) were red painted by a PO, and it is one of my goals to get rid of the awful paint

[Tommd]

Yes, yours is probably a replacement. When you remove the PP check if the flywheel is also drilled for the 9.5 inch PP. it almost certainly will be. If so, go with the 9.5 inch diaphragm type.
Tom

[Philippe-J.]

Having removed the clutch, I can see that it was secured onto the flywheel by six 3/8" screws, on a circle of 290 mm in diameter.
I can also see another circle of 275 mm in diameter, that has six 5/16" threads + 3 smooth holes.
Can anyone confirm that those are ok for a 9.5" diaphragm clutch?
Thanks for your help.

[Tommd]

I am not there, but from what I see, yes, it looks like you have the six holes for the bolts and the three holes for the three dowel pins you will need to obtain and then the 9.5 inch clutch and PP should bolt right up.
Tom

[Philippe-J.]

Thank you Tom.
The problem with such spare parts is you can't find technical drawings of them with dimensions, hence my questions. Let's bet it'll be ok and order a 9.5" diaphragm clutch

Philippe

[abowie]

I can also see another circle of 375 mm in diameter, that has six 5/16" threads + 3 smooth holes.

The setscrews that hold the 9.5" clutch should be 3/8", not 5/16".

https://www.sngbarratt.com/English/UK/p ... 202473483)

I wonder if that's why your car was fitted with a 10" clutch. Is the engine number stamped on your flywheel, and if so does it correspond to the one on your block?

[Tommd]

Andrew, I just replaced the clutch and PP in my 1967 OTS. I also had a 10 inch spring type PP as shown above. I replaced it with the 9.5 diaphragm PP below. I removed 3/8 inch bolts and had to purchase 5/16 inch to fit the inner ring of threaded holes. I also believe the dowel pins were a different size, I believe 1/4 inch, and instead of two, it now required three.
Tom

[Philippe-J.]

Actually Tom your configuration looks very much like mine. And my OTS was imported from the US, is this coincidence? I checked the size of the dowel holes: 1/4" too. Just a question: what is "PP"?
Andrew: the number stamped on the flywheel is the same as on the engine block and the Heritage Certificate. I checked the size of the 6 threads with a tapper, the 5/16" is a perfect fit.
Thank you Tom for your report, it secures my decision to order a 9.5" diaphragm "PP" too.
Philippe

[Tommd]

Philippe- No coincidence. From what I had researched, most all 4.2 flywheels are drilled for both. At least back into 1966.
PP is pressure plate.
Tom

[Philippe-J.]

What is more surprising though is that we both found our later cars with a 10" spring clutch when they should be with a 9.5" diaphragm one. Was this a US way to do with E Types?
Anyway I ordered the later for my car in place of the 10" one, and the 5/16'' screws (I had to insist to my provider who hadn't heard of this configuration). Let's hope everything will be ok now.

[politeperson]

Philippe,
When you reassemble it with the gearbox on the engine, check the movement of the clutch arm in relation to the bellhousing slot.
There was confusion about the overall depth of the the release bearing and the associated part number.
This lead to the clutch arm hitting the bellhousing before the clutch was properly released, as the clutch pedal was pressed.
Best to find out before you fit it all into the car.

[Philippe-J.]

Good advise James, thanks!
I'll do a dry test as soon as my gearbox is reassembled and I get the clutch parts. I won't start the engine overhaul before that test...

[Philippe-J.]

I asked my mechanics to reskin my flywheel. Seing it, he thinks that the outer circle of 3/8" threads were made afterwards. So a PO changed the original 9.5" clutch with an older 10". It was a time when E Types were cheap used cars, and there was no expense they deserved.

[Tommd]

Philippe, at this point it is not really important, but if you do some searches, you will find that most if not all were drilled for both 10 and 9.5 inch. There is a good chance your car was originally equipped with a 10 inch diaphragm PP and was later replaced with a 10 inch spring type.
Tom

[Philippe-J.]

A new question rises now, about the bolts to secure the clutch mechanism to the flywheel.
They are 7/8 x 5/16". But I read somewhere that they should be grade 8 (5 strips on their head).
Do you confirm?
In SNG's catalogue, this is not specified. I guess I would get the common grade 5. Would you indicate a provider that commits with such a specification?
Thanks.

[Tommd]

Are grade 8 not readily available in a hardware store near you?
Tom

[Philippe-J.]

"hardware store near [me]" is an unlikely statement:
- it's night impossible to get imperial stuff in France
- good hardware store turned all virtual in 2025, everything is e-something now.
The only problem with e-trade is it's difficult to get accurate information about what you are buying, e.g. the grade of the bolts. Hence my question.
Philippe

[mgcjag]

The parts catalogue as far as im aware depending where you look specifies UFS131/8R or UFS137/8R....it has been mentioned that the 7 was possibly a typo so the correct one is UFS131/8R.....you can search her on on JL for more info....so its a set screw....sold by the usual suppliers.....dont forget the dowels take sheer....set screws clamp it down....Steve

[Philippe-J.]

Thank you Steve for this.
I notice that "UFS131/8R" is not enough to be sure about the grade. Some usuals give it (e.g. Moss says "grade 8"), some don't (e.g. SNG). Anyway I can order them to Moss now, that I found from your post, so !

As for the dowels, I am aware about them. I had to struggle to get them with the right diameter from the provider of the clutch mechanism himself. He would not sale them compatible with it

Philippe

[mgcjag]

These set screws arnt grade 8 as far as im aware...they will be standard grade 5 and are used in various other locations on E types