Morris Minor Owners Club

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Could somebody please confirm this as a 1098 pressure plate?
I need to make sure this will fit my Minor.

Spridget clutch is smaller than Minor clutch - but check with seller. If it's for Spridget it won't be suitable for Minor.

So, the engine/gearboxes are the same, but the clutch is smaller on a Sprite?

Yes - engine/box not exactly identical but 'similar' - and it's hydraulically operated clutch on Spridget.

Right. I'm still converting my '60 minor 948 over to the 1098 gearbox. All I need is a 1098 clutch and pressure plate.
I thought the Sprite plate I linked to looked identical to the one listed on ESM.

It may be - it may not actually be a Spridget pressure assembly! Ask them what diameter it is. If you still have the Minor 948 flywheel - you need the (smaller) 948 Minor clutch assembly anyway. If you want to use 1098 clutch assembly - then you need a 1098 Minor flywheel. The backplate on the 948 engine is also thinner than the 1098 backplate - ideally you want the 1098 backplate too although I 'think' you will get away with using the early backplate. Someone who actually knows will probably be along in a minute or two!

Haynes Midget Manual lists the following clutches:-
948 cc, 6.25 in, spring plate (Minor clutch)
1098 cc, 7.25 in, spring plate (Minor clutch)
1275 cc, 6.5 in, diaphram plate
The illustrated clutch is suitable for a 1098 Minor

Ahhhh - so only the 1275 had the different clutch - thanks for finding that Mike ! On the gearbox swop though - you still need to match the clutch to the flywheel - so if 948 flywheel it's the smaller pressure pad assembly and plate you need. usually the pressure pad outlives the plate roughly 2:1 - although some replace everything to avoid any future trouble. Certainly stick a new carbon thrust (or roller replacement) on the release fork.

I have both a 948 and a 1098 flywheel readily available.
I just needed to know what parts cross between MG/Austin/Morris clutch and gearboxes so I can save some $$$!

(There needs to be a sticky thread on the parts needed for a 948 to 1098 gearbox swap!)

As far as I am aware, the roller thrust is only available for the 1098 and 1275 manual conversion.
The thrust for the 918/803/948 is different to the 1098/1275 manual.

Use the 1098 flywheel - and ask the supplier what diameter the pressure plate is on the pressure assembly.

I did a 948 engine into a 1098 car about 2 years ago and I don't recall changing anything else, so, my "assumption" is that if you fit a 1098 box and 1098 clutch you will be on the right track.....

I have a distant memory of a friend fitting a 1098 engine and clutch assembly onto a 948 box in his Frogeye.

Well, pulled out the motor last night, and this is what I've come up with.
There is no combination of 1098/948 clutch parts that will work well. Using a 948 clutch and pressure plate leaves the release bearing too far away from the pressure plate, no matter which fork you use. You have to use the 1098 clutch, pressure plate, flywheel and fork for proper clutch travel and geometry.

That is the best combination by far - but I do think the 948 clutch can be 'made' to work ok if determined!

Here is a photo. This is taken with a LHD 1098 gearbox, fork and release bearing, and 948 flywheel and clutch and pressure plate. Everything lines up well enough, but there is very little room left for release fork travel.
The clutch did not release properly for me with this setup.
Since the 1098 pressure plate is taller, it should move the fork back further, resolving this issue.

I think there are thicker release bearings available - otherwise I suppose the slot could be opened out a bit - but the bearing may then just start to foul the input shaft.
Was this pic taken with the 'thin' 948 backplate on the engine ? And what if the 948 release arm is fitted - any different ?

a. I don't know which backplate I have. Doesn't seem overly thin to me.
b. With the 948 release arm, the bearing was not centered on the pressure plate. Wrong geometry.

a - The 948 bacplate is more or less 'sheet steel' - about 1/8" thick and the 1098 backplate is thicker about 5/16" thick plate.
b - Yes - I guess it would be
Good research work done here Bossk! Will be a usefull thread for others in the future.

Well, that answers that. The backplate is the original that came with the 948 car. I can safely assume that a 1098 backplate would move things even further away, leaving even less room for release fork travel.