Morris Minor Owners Club

Mike
I have in the past slightly enlarged the clutch lever hole in the bell housing to get the lever travel satisfactory.
I know it should not need it but it had to be done to get it to work satisfactorily.
You have the correct 1098cc clutch release lever (flats on rear edge).
Phil

Just to finish this off (delayed by family, friends and village affairs getting in the way) I fitted a 1275 engine carbon release bearing as shown on the right in Rob Thomas's photo above and also filed the rear of the opening in the bell housing where the clutch lever had been touching the bell housing. Now when the clutch pedal is fully depressed the lever looks like this[frame][/frame]
which gives a gap of about 5mm between the lever and the housing - the same as the extra height of the 1275 release bearing shown in Rob's photo. Quite why I had to do all this to get clearance I really don't know. But if you have to try it, here's a WARNING.
There's a lot of these 1275 release bearings out there in which the carbon material is only retained in the carrier by a (single) roll pin rather than a proper fit. (There's much discussion on the interweb about their short lives.) So acting on Phil's advice I contacted Peter May Engineering Ltd where they knew exactly the quality problem and supplied the right item for £12.90 (plus VAT) with immediate delivery. So now all's well!

Regards to all and thanks for all the good advice, MikeN.

Mike,

Is the engine a 948 or 1098? What rear plate is fitted? The thin 948 or thick 1098?

The gearbox front cover is different on the smoothcase and ribcase - the pivot pin on the 948 is higher than the 1098 and the bolt pattern is also different between the two covers.

I have long recommended the use of the 1275 release bearing to get extra movement - but surely there must be a better material to use in it than 'graphite' these days ? PEEK , UHMWP - something like that ?

With too much movement - there is a real danger that the release fingers will hit the centre plate springs.
Changing the release bearing specification must be exercised with care!
Ball bearing type release bearing is the way forward.
Phil[frame][/frame]

Is that HAZ marking on the bearing surface from not having the bearing concentric with the clutch cover face? That would be the only (small) downside to a roller release bearing, I guess.

Are we of the collective opinion that the whole clutch release arm hasn't been bent backwards?

I suspect that it is - unfortunately unless you can get the faces completely in line there is not much you can do about it.
The advantage of the graphite bearing it that it will wear so ending up in line.
The release bearing on my Minor which has a Ford derived gearbox and clutch uses the Marina ball bearing type release bearing mounted on an adapter sitting in a MG 1275cc Midget release arm. There is enough slack in the pivot point to allow for any misalignment between release bearing and pressure plate bearing pad. So far it has never given me any problems but I did have to bend the release arm to suit and grind a little out of the bell housing to allow sufficient for and aft movement. There again nearly everything about my Minor is hybrid
Phil

Some while ago I fitted a ball race thrust bearing, and had to remove the thrust plate from the clutch, as at that time the ball thrust race was much deeper than the carbon one, and the ball race ones available today.

The support for the release arm on the Toyota T50 conversion is not quite as good as the original A-Series 'box, and on the initial press of the pedal, there was a slight shudder while the thrust race sorted out where it wanted to go. I couldn't see the benefit, so it was removed after only a few thousand miles.

The set up now is a standard 1275 Midget diaphragm pressure plate, special AP Racing centre plate with Midget facings and Toyota spline, 1275 Midget carbon thrust and everything else standard Minor mechanical linkage. Even with a diaphragm clutch, it is slightly heavier than a typical 'modern', but that just encourages good behaviour when in stationary traffic of selecting neutral, instead of riding the clutch!

Well folks here's an update, alas delayed by family, friends and village affairs.
With the engine and gearbox back in the car and the car clear of the ground on four axle stands I still couldn't get a clean engagement of the gears even with the clutch pedal pressed to the floor and hardly any clearance i.e. the recommended pedal clearance reduced from the 40mm in the manual to about 10mm.
What to do? Well, I asked Phil above to come and give it a good staring at as we pulled the g'box off the engine and give an opinion on what he then saw. We took the clutch off the flywheel and the only thing that is below par is the thrust plate against which the clutch thrust bearing presses. Currently it's about 8.8-8.9mm thick; is this low?
See here[frame][/frame]
Ah, not as in focus as I thought, but you can see the grooves in the surface caused, I suspect, by a previous owner wearing out a previous carbon bearing. I'll replace this and report how I get on. (I'm getting real good at pulling out and then replacing engine and transmissions!)

First, a note to Brian Gosling custodian of the club's spares. Our usual suppliers no longer list this plate as a separate item ; has anyone got a spare?

Regards, MikeN.

Here's a better picture of the offending thrust bearing.[frame][/frame]
The face is worn into a "bowl" shape and with a steel ruler laid across it I find that there's a general depression of about 0.008 inches at the inner edge but with deeper cuts (say about 12-15 thou) in the face.
MikeN.

Mike
Looking at and comparing the clutch cover/carbon thrust bearing plate in the link below I would say that your carbon thrust bearing plate is seriously worn.
http://www.ebay.co.uk/itm/Morris-Minor- ... xyaoFSE5DP
Phil

Mike,

All the boxes are the same length - Minor, Midget, A35, A40 etc., so that should not cause the engine to be too far forward. Are the gearbox 'U' mounting brackets the right way round and also the front towers?

If you look at the clutch relay shaft, between the gearbox and the chassis rail, are the two ends reasonably in line? If the engine is too far forward, I would expect to see the gearbox end of the relay shaft further forward than the chassis rail, and the relay shaft itself at an angle, Is it?

Richard
What is happening is that the front face of the carbon release bearing is too far from the face of the clutch cover carbon thrust plate and the only thing I could find was that the plate against which carbon thrust presses was badly worn.
The clutch was working before the work being undertaken and the fingers of the clutch pressure plate have not been adjusted or played with.
Phil

Phil,

Ah! I was addressing a comment earlier in the post - I am not suggesting that the position of the engine will have an effect on the throw required to actuate the clutch. Sorry for any confusion!

Richard
Thanks for coming back to me.
A summery of what was examined and what was found:-
The clutch release lever and its operation before the gearbox was split from the engine was examined and all seemed to be well except for the travel to engage the carbon thrust against the carbon thrust pad.
The relationship between engine and gearbox was examined and found to be as it should be.
The clutch lever and its operation after the gear box and engine were separated was examined and except for a small amount of wear in the release lever pivot bush/bolt all was well.
The release lever (rearwards) and carbon thrust (forwards) had enough travel for the carbon thrust to engage with the first motion shaft.
The release lever was examined and did not appear to be bent or distorted.
The clutch cover was examined and was found to be serviceable - except for the carbon thrust pad which was found to be badley worn.
The centre plate was examined and found to be serviceable - it looks as if it had only just been fitted.
The carbon release bearing is new.
Note: The gearbox front cover is the correct one Pt No: 22G118 and confirmed by Mike earlier in this thread.
The relay shaft and linkagages were examined and appeared to be serviceable as was the clutch pedal.
The flywheel was examined and found to be serviceable.
A small amount of end float in the crankshaft was detected but when measured was not considered excessive.
A mystery indeed especially as the clutch was working satisfactorly according to Mike before the work was undertaken.
The gearbox & engine were removed when I came to examine the clutch problem so did not have a chance to road test the car and the clutch operation.
The gearbox was not internally examined as it had been working satisfactorily before the current work was started.
For comparison - when a 1275cc clutch release arm is laid on its back the operating rod hole is raked 4.9mm higher (or further forward) than the lever pivot point.
All of the 1098cc clutch release levers I have looked at appear without measuring to be straight and not raked forward.
I have in the past when fitting mix and match clutch assys had to bend the release arm to get the clutch to work correctly.
I am not suggesting that the arm should be bent to suit but if nothing else can be found to be causing the clutch problem it may be something to consider as a means to an end.
Phil

Thanks for your report, Phil.
I've searched the main parts suppliers (inc ebay) and can't find a clutch thrust pad as a separate item to be purchased. So at the moment I've e-mailed Bryan Gostling of MMOC spares and perhaps I'll get lucky. If not, then perhaps a cheap worn clutch off a member just for the pad. (And finally, ebay again.)
We'll see how it goes, MikeN.

Here is a useful link which might help identify the issue..

http://www.gerardsgarage.com/Garage/Tec ... arings.htm

Taupe

Taupe
Many thanks for the link. Now on my favorites list
The clutch release lever is Pt No: 22G166 and the gear box front cover is Pt No: 22G118 - so the right component parts are being used.
Even with the lever required to move through the dead ground before the carbon thrust contacts the release bearing thrust plate the thrust bearing has sufficient forward movement to enable the clutch centre plate to be released when the clutch pedal is depressed.
If the release arm was slightly bent rearwards there is still sufficient movement within the linkage/bell housing opening etc. to release the clutch centre plate.
I checked the inside of the new carbon thrust and there was no sign of the new carbon thrust bearing coming into contact with the first motion shaft which could happen if the release lever/carbon thrust over-centred.
A new pressure plate may be the answer.
Phil