Morris Minor Owners Club

The outer face of the hub bearing should be proud of the outer face of the hub as per stated in the wksp manual.
You can get suitable/different thickness gasket paper in different thicknesses from 'e' bay.
That proudness is what grips the hub bearing and stops the outer part of the bearing rotating and removes the possibility of lateral movement of the hub.

Ok thanks Phil.

Another question-"nip", and "float"-what do those terms mean please?

Thanks, Neil

'Nip' means in this case the retaining grip/load that is applied to the bearing in the hub or on the axle stub.

'Float' means in this case the ability of the bearing to move in the hub or on the axle stub.

Ok thanks.

So I read that as meaning that a small amount of "play" of the hub on the bearing is acceptable?

The bearing is in the hub, it was pressed in, with bearing lock smeared on the outer, and held in position until the bearing lock set. The outer part of the bearing is not proud of the hub, I've measured that using a dial indicator. I did this about 18 months ago, the bearing was new then, and has since done about 1500 miles.

Looking at your explanation of calculating gasket thickness on P1, the difference between the bearing inner race and the hub face is 0.2mm. Subtracting the median float value of 0.002" (0.0508mm) gives 0.1492mm, and my gasket measures 0.15mm (all measurements in metric, I only have a metric micrometer), which is close enough for me.

I have done the hub nut up as far as I can (I might get another perhaps 1/8th of a turn, but that's a job for tomorrow or the weekend). There is a small amount of play when I grip the hub, it is, as far as I can tell, play within the bearing, i.e. between the inner & outer races, not play of the bearing on the stub axle, or of the bearing in the hub.

Can you remember if the bearing was a C3 type bearing?
The C3 type bearing has more play and if fitted to the Minor hub can result in being able to get movement at the wheel rim.
There has been a considerable amount of discussion regarding the fitment of C3 bearings on this site - use the search facility to find details.
The fitted hub without the half-shaft in place and because it is a single row ball bearing race will allow a very small amount of rocking movement of the hub.
The bearing when fitted should be slightly proud of the outer face of the hub (see wksp manual for details). The amount of grip is then determined by the thickness of the gasket paper.
There should be no float of the bearing on the axle stub when the hub nut is tight. There is no stated torque for the hub nut but it must be tight - but not so tight as to strip the threads.

FWIW, this is the original workshop tool for tightening the hub nut on the Austin axles. The thick part is hollow and has a hexagonal cut-out to fit the nut whilst the 2 thinner bits fit down inside the axle casing to line things up. One end for small axles (Minor, Midget etc) and the other end for, presumably, MGB etc.

Rob
Many thanks for the photo above of BMC/Churchill special tool 18G152.
The tool is double ended and is suitable for the 'A' Series axle and the 'B' Series axle.
The round bar ends fit into the axle tube and help keep the tool on the narrow hub nut.
They do come up for sale on 'e' bay now and again but they are not cheap.
I have seen a new replica single ended tool being offered for sale on 'e' bay but is only suitable for the 'B' Series axle.
Phil

Found this one in the boot of a Convertible I bought for £2000, including the Alta head. Bonus!!

Some people have all the luck

In the end, I got a 1⅞" box spanner. Does the job ok, if a little tricky to keep aligned on the thin hub nut.
My wallet is £43 lighter now though.....

While on the subject here has anyone fitted the rear wheel bearing as supplied by ESM ?, I can feel a little roughness/clicking in one so the time is coming to replace I think. Curious to make sure the quality is there and the whole lot is not going to disintegrate on me.

The ESM kit has a FAG bearing, they are made either in Germany or the far east but all bearings are inspected in Germany. They are as good a quality as any other (SKF etc). The bearing is a C3, This means that its designed for moderate heat expansion to allow for the diff oil to warm up.

Being C3 also means that the clearances are greater and play can be felt in the bearing when installed.
There has been a lot of discussion on this web about the use of C3 bearings for the Minor rear hubs.
Use the search facility to find the relative discussion.

Thanks guys, yes I have read the discussions and there is a split of opinion on the use of C3 bearings. Roy had some strong opinions on the subject. I shall do some searching. The R&Ms fitted have had thier life, really rough and feels like it has some flat spots. Worryingly the hub nut wasn't that tight either, not much beyond nipped as it came undone while I was tapping the locktab back, fortunately the bearing has not spun.

A good read https://shop.eriks.nl/en/bearing-clearance/

Paul
Many thanks for the link.
Whilst I am not a fan of C3 Minor rear hub bearings BL/UNIPART latterly provided C3 hub bearings as the defacto Minor rear hub bearing.

Phil
I think that it all depends on the quality of the bearing, if you are going to purchase a cheap far eastern bearing off eBay then it may have a lot of play. The kit that you highlighted is cheaper than buying the separate components and it does have a recognised bearing which should be of good quality. If the seals etc aren't required, you could be better off wandering down to your local bearing supplier, you could then ask for C2 or C3, both are suitable. I suppose that it all come down to personal choice.
Iirc, my local bearing supplier stopped selling wheel bearing kits as they couldn't compete with eBay selling cheap far eastern kits with rubbish bearings.

The problem is the C3 specification and not the quality. Even good quality C3 bearings have clearances within the C3 specification which can produce play at the hub.
If you look at the various links the C3 specification is for bearings exposed to heat which will close up the clearances.
The Minor axle in my honest opinion will never get hot enough to close up the clearances in the C3 bearing.
I would suggest that the supply of C3 bearings has more to do with their availability and size than anything else.

philthehill wrote: ↑Sun May 30, 2021 11:17 am
If you look at the various links the C3 specification is for bearings exposed to heat which will close up the clearances.
The Minor axle in my honest opinion will never get hot enough to close up the clearances in the C3 bearing.

I would assume that BMC would consider all the roads that the average new car would travel on for the annual 12,000 miles. Mine only does 3,000 miles per year and never goes on the motorway. This morning I changed the diff oil after a 20 mile run, it was only hand warm.