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MG Midget and Sprite Technical - Release bearings

OK, I might be losing it...

In midget release bearings there are three different offsets of the mounting lugs. They correspond to the three different clutches for 948, 1098, 1275. If the carbon working face is sat flat on a bench then they can be viewed as low, medium, high. High is about an inch offset to the centre of the lug.

My last batch I suspect has been boxed wrongly. Or I might have it scrambled in my head...

Which is high, which is medium, which is low?

Paul Walbran

From memory, I think the low one is the 948, although you would expect it to be for the 1098, as that has the deeper clutch, but I don't *think* it is.

I have a new 1275 bearing in the garage that I can measure for you.
Dave O'Neill 2

I think I've seen the pic elsewhere but it's the 4th image in this ebay listing https://www.ebay.co.uk/itm/183472542773 showing the 3 release bearings together and the engine size.
David Billington

Release bearings

948 is 1/2 inch centre of spigot hole to carbon face. Spring Clutch.
1098 is 3/4 inch centre of spigot to carbon face. Spring clutch.
1275 is a tad under 1” centre of spigot to carbon face. Diaphragm clutch

I make a roller release bearing as a substitute for the Crb on 1275 (top pic)
Robin Human makes a roller release bearing as a substitute for the Crb on both 948 & 1098. (948 shown lower pic).





Alan Anstead

I knew the answer to this. It's in my notes, but I knew also that Alan would be right on top of it and he knows this subject way better than me so I held my tongue.
Alan's the Man. 👍😉
Greybeard

Woo-hoo! I'm not losing it!
The packaging labels are wrong, as I suspected.
Thanks all!
Paul Walbran

Paul
It is usually a 1098 CRB that gets passed off as 1275. The carbons usually are 4mm proud of the castings. A 1098 CRB will work on a 1275 but perhaps with compromised longevity.
Alan Anstead

Thanks Alan, yes that's what I have usually found. In this case I received both types, but the labels the wrong way round. That's when I wondered if my memory might be going gaga :) Go to find its not!
Paul Walbran

The 948 is the shortest because it uses a tinplate back plate. The 1098 is next because the back plate is a lot thicker so they moved the pivot point to compensate. They both use springs so the distance between the pad and flywheel face is the same. The 1275, being a diaphragm clutch, is different by design so they had to move the pivot further away to compensate.
Rob
MG Moneypit

This thread was discussed between 22/05/2025 and 23/05/2025

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.