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MG Midget and Sprite Technical - Identifying a clutch

I need help identifying my clutch. Maybe someone here has a copy of a parts catalogue.

This is for my type 9 fitted to a 1275 engine. I did the installation in the car myself 25 or so years ago, sourcing and making components rather than buying in an expensive 'kit'.

I think I used a standard 1275 pressure plate. It is of the fingered variety stamped with QY13001 and Made in Great Bitain. One of the fingers has 2201 stamped on it. The pressure plate is 167mm diameter. I assume this is a standard Quinton Hazell clutch cover. Critically, the centre hole between the fingers needs to clear the guide nose on my concentric slave cylinder (another DIY job)

The driven plate for the t9 needs to have 23 splines, so isn't for a standard 1275 ribcase. It was supplied by a local motor factors (no longer exists) and a helpful individual went through about a dozen boxes looking and measuring plates to find one. I have a vague notion it was for a Hillman Avenger, but that may not be true. The plate itself is 165mm diameter, 23 spline and the only identification is Made in the UK and a single letter Q. At a pinch I could re-use it though it is fairly worn, measuring 5.87mm thick where the linings are clamped tight with the rivets. It really needs replacing whilst its out of the car.

Can anyone advise or provide any info about what these parts are that I need to order?
GuyW

My PDF QH clutch catalogue show the Avenger as a 190mm and 25.4x23 but maybe very early ones used a smaller clutch. It doesn't list the early Escort 165mm clutch which I use with a 1275 clutch cover and Ford 4 speed box. All listed 25.4x23 plates are 190mm or larger. Maybe you'll have to get yours rebuilt.
David Billington

Thanks David. So maybe it wasn't an Avenger one then. A long time ago now but the chap was very keen to help, opening one box after another until he found this one.

Perhaps it is an early Escort one,like yours then? It is certainly 165mm diameter. Would yours be for a mk 1 escort? Do you know what year or have a part number please?
GuyW

Guy,

IIRC the one I use is for the smallest engine mk1 Escort but the spline is different, smaller OD fewer splines, so wouldn't suit yours. Attached PDF shows some Ford applications and interestingly mk3 Escort shows a 165mm clutch so maybe you could investigate whether the centres can be swapped. It doesn't show the smallest engined mk1 in that list but I found it as the local motor factor had a similar list showing it but that was years ago pre PDFs and actually printed paper.
David Billington

Thanks David. I was under the impression that a 23 spline input shaft for a t9 would be more ubiquitous than that table suggests.
The plate I have looks in good condition, at least as regards the splines and the central web, if that's what one would call it. So maybe I just need a company that reline clutches. There are lots if I google it but has anyone experience of this? I would rather start from a recommendation.
GuyW

Whilst I am picking brains, - well David's at least, what lining thickness would there be on a new plate clear of the rivet heads? This worn one is consistently 0.54 lining clearance over each of the rivet heads.
GuyW

Guy,

I think to important dimension is the thickness of the whole plate across both linings, clamped to compress the spring plate between them.
David Billington

Well that was the 5.87mm. I dont know how that compares to a fresh unused plate.

The limit would surely be when the lining is down to the rivet heads, then scoring the flywheel. I only have 0.54mm before that happening. As it is, both flywheel face (which was skimmed when I first assembled this) and the pressure plate, are unmarked and clean with no scratches, wear grooves or blueing.
GuyW

Guy,

This thread https://forums.thelotusforums.com/topic/81691-clutch-disk-thickness-specs/ tallies with what I recall the normal new thickness to be about 8mm typically. According to that yours should be replaced.

I had a chat with my neighbour a few years ago and he mentioned an old shop in Bath where you could get your brakes and clutches relined or purchase the material and rivets to do it yourself, long gone now, he thinks he still has some liner rivets in a drawer in his workshop.
David Billington

Thanks. I have never thought about this before but the 'web' that the friction linings are rivetted to is clearly designed to be intentionally wavey and springs the linings apart by a few millimetres when the plate is not compressed. i.e. When not engaged. One reason could be to give a smoother take up, or at least to reduce shock on the components. The lining between rivets is bowed outwards, making first light contact with flywheel and pressure plate to start spinning before getting fully clamped as the clutch engages. A sort of automatic clutch slip.

Very necessary therefore with this type of plate to measure where both the linings are clamped tight at the same point, where the rivets are. As you point out, mine at 5.87 are well within the worn out dimension of the lotus plates. I still think the ultimate worn out status is when wear reaches the rivet heads.

Relining seems to be the best solution for me but out of interest, what clutch is supplied with the Frontline kits? What diameter driven plate?

GuyW

Guy, You're spot on with the wavey plate softening the takeup. i had an mgb that the linings came loose on and took it to the local clutch/brake fella and made the decision to bond a new lining on then rivit as well. The bonding(glue)filled up all the gap between the two linings-the result was a really grabby clutch, smooth takeoffs were a thing of the past.
William Revit

I had a 1275 flywheel modified for a clutch cover marked with QY13000 and I have no idea what that came out of. It does look Ford like but it is not marked with any manufacturer.
The clutch cover measures 7.5 inches and I use a Hillman Avenger clutch plate to drive a Type 9 input shaft. Your clutch plate of 6.5 inches sounds like the hybrid plate made by the Type 9 gearbox kit suppliers so you can use the standard 1275 clutch cover.
My clutch cover has fingers with curly ends and I used a Cortina release bearing (I think) which is very like the release bearings Alan Anstead uses in his roller release bearings but is a slighter bigger diameter so I could retain the Type 9 nose plate without having to cut the tube off.

At the time (7 or 8 years ago) I spent hours on Google trying to find out what car the cover plate originally fitted, without any luck.

If anyone knows I would also be very interested.
Rob
MG Moneypit

Well your cover is only one digit different from mine, which is a standard 1275 mg one. Or is as far as I remember. It certainly fits the flywheel with no modification.

If, as you say, the frontline kit uses the same 165mm driven plate that may be another option. Only their website is awful! Home page is all in thin red lettering in a black background and just impossible to read. I couldnt make out what it was even about or find a link to parts section or even a "contact us" form.
Gave up!
GuyW

Guy,

I had a quick look at the FL site and it's changed quite a bit from the last time I looked and needed quite a few scripts enabled to function. Clicking on horizontal bars top right gets a menu you can select spares from which brings up another page and can see lots of 5 speed options but no spares such as driven plates, maybe he expects users to buy another conversion like with the front suspension units when the plate wears out ;).
David Billington

Guy,

It might we worth contacting jlhmorrisminors

ISTR he used to post on the forum and was converting minors and midgets with his own designed upgrades etc - always seemed a useful chap in the world of mods.

Just a thought as I expect he knows the market.

R.
richard b

Yes, might do that though I have had the following very quick reply from saftek:

With reference to your enquiry

Regarding the reline of your Sprite clutch plate
Total cost to reline - £45.30
This includes vat & return
Turnaround 2-3 days

I doubt anyone is going to do much better!
GuyW

http://shop.trikingsportscars.co.uk/product/clutch-plate-ford-gearbox/


Think this may help ?
richard b

Yes Richard. That would have done but at more than twice the price. I think I will go for relining!
GuyW

Worth having a good look at the splines and the internals as it will have had a fair bit of flexing over its life !

Still worth getting it in the archives for others - assuming they can ever find it !
richard b

I can't see any damage but spoke to Saftek who say they dismantle, clean and inspect to be sure that the body is good before relining.
GuyW

I do have an old AP racing cover and plate for a Type 9 that has sat in my garage for a long time that needs a new home. I don't think it is worth anything but it will be heavy to post. AP racing replaced that design with a different one before ceasing manufacture altogether (which I am keeping as my new spare) so I now have something similar from Helix in the car

Most of the Sierra and Ford covers and plates, even when standard should cope with a warmed over 1275.

I think originally it was Hillman Hunter rather than Hillman Avenger that was the compatible cover but might be wrong.
Daniel

Thanks Daniel. I have dispatched the old one for relining now. So unless they reject it on condition grounds then I am sorted on this.
GuyW

Got my clutch plate back. Looks good to me. Now measures 8.2mm overall thickness when clamped (previously 5.87)

Nicely cleaned up centre plate.
£45 well spent.
Incidentally, I had done 80,000 on the old one and it still had a bit to go.





GuyW

This thread was discussed between 09/09/2024 and 18/09/2024

MG Midget and Sprite Technical index

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