My first Ribcase

[David W.]

Another bit of information:
David - Hi again! Glad it all worked out OK! Yes, since they discontinued the original main case bearing there has been a lot of confusion on the proper clearances for the bearings. The manufacturers of the new center bearing should point that out when they include the shim with the bearing. Otherwise, like you did there is no way of knowing where the shim goes. We provide a document with our rebuild kits that show this shim and where to place it properly.



I am also glad you realized the shim for the input shaft goes between the lock washer for the lock nut and the bearing. You would be surprised at how many transmissions we get where they put the spacer between the gear and the bearing! That really messes up the alignment for the input shaft! as it moves the input shaft rearward into the mainshaft! Causes the 3rd and 4th synchros to burn up and wipes out the 3rd/4th sliding hub as well.



Let me know if i can be of any other help.



John

[philthehill]

I may be looking in the wrong places but cannot find anything regarding the change of dimensions of the main shaft (3rd Motion shaft) bearing. Is this just an across the Atlantic problem as I have searched the web and looked at the various suppliers for the bearing Part No 10G184 and there is no mention of changes to dimensions. I have looked for various threads relating to this bearing and cannot find anything.
There must be something out there but where?
I am certain that someone in the Morris world knows the answer!!!!!

[bmcecosse]

I have heard this story on the Mini forums - but didn't think to cross apply it to this Minor box. It is of course the same bearing, and yes it appears the original is not available any more - and a slightly thinner bearing is supplied as substitute.

[philthehill]

Supplying a suitable bearing is alright if you have the instructions as advised/provided by John at Quantum Mechanics but do the suppliers provide that information? I would have thought by now that there would have been a thread relating to the fitting of the different bearing and feedback but as I said I may be looking in the wrong place or calling the thread by the wrong name but I cannot find anything on this site or on the web. I just want to be sure that the problems encountered by David.W are not encountered by anyone else and that there are clear and concise instructions available.

[David W.]

Strictly speaking, I don't have a Minor Box. It's a "rebuildable core" from a salvage source who said it's from a Midget. The side of the case is marked "MG 13179."
Here are two bearings. Old on the left, new on the right.
New bearing measures .625 along the axis.
Old bearing measures .625 on the outer race, .720 at the inner race.[frame][/frame][frame][/frame][frame][/frame]

[bmcecosse]

Thanks David (and Quantum!) - this is excellent information for anyone rebuilding a Minor box.

[philthehill]

David
Many thanks for the info.
Could you persuade John at Quantum Mechanics to post his fitting instructions on this thread so all can be completely clear what is required me included as many a Midget box is fitted to Minors over here.
As an aside I think John needs a bigger hammer!!!!!!!!!!!!!!!

[David W.]

He's not using a hammer, it's an "INERTIAL MODULATOR."

[philthehill]

David
Thanks for the revised description of the whatever he is holding.

Now I am as confused as ever over these bearings because I have looked on the Moss website for MG gearboxes both 1098cc and 1275cc and the 1098cc Minor gearbox all the bearings are available with no reference to them being alternative bearings or requiring extra shimming.
I have tabulated the bearings below:-

1098cc Mg/Sprite gearbox.

First Motion shaft bearing Pt No: 2A3245.
3rd Motion shaft bearing Pt No: 2A3245.

1275cc Mg/Sprite gearbox.

First Motion shaft bearing Pt No: 2A3245.
3rd Motion shaft bearing Pt No: 22A465.

Minor 1098cc (Rib case)

First Motion shaft bearing Pt No: 2A3245.
3rd Motion shaft Pt No: 22A465.

Can anyone shed more light on this?

[bmcecosse]

They are giving it the original part number - but they supply a 'modern' alternative that is thinner as shown above, and a shim to make up the difference. The problem has been that they don't tell us where to put the shim...... All this is handy for me since I have a Mini box to rebuild - when I can get round to it..........

[David W.]

I ordered my bearings from ESM:
1 x 1st Motion Shaft Bearing (2A3245) (10G141) = £9.95
1 x 3rd Motion Shaft Bearing (22A465) (10G184) = £12.50
The 10G numbers are what is shown in the Morris Minor parts manual, pages 92/93.
They both measure the same in all aspects, but one comes with the shim and snap ring.
Moss USA doesn't support the Morris Minor, but has lots of parts if you know where to look.
On this page, there is a different pn and price for the 1098 rear bearing, but no indication of what is different.
http://www.mossmotors.com/Shop/ViewProd ... D=29287#43
This is as much light as I can shed so far.
David

[philthehill]

I take it ESM did not supply fitting instructions otherwise you would have placed the washer/shin on the correct side of the bearing!

[David W.]

This whole journey started with engine noises. I decided to upgrade the gearbox since everything was out of the car anyway.
I'm waiting for engine parts to start that reassembly.
I've noticed that the input shaft is about 5/32 longer on the ribcase as compared to smoothcase.
The backplate of the 948 engine fits the ribcase as far as all the bolt holes lining up. (It may not actually be a 948 backplate.) I've read that a backplate change is necessary for the ribcase upgrade. Is the later backplate thicker by 5/32?
Am I going to have problems when it comes time to mate the gearbox to the engine because of that 5/32?
When I get the engine back together, I'm going to mate the two and test everything I can on a bench before installation.[frame][/frame][frame][/frame]

[IslipMinor]

The gearbox bearings are common to all in-line 'makes', MG, Sprite, Austin, Morris etc, but the rear, 3rd motion shaft, bearings are different between 948 (+?803) and 1098/1275.

The 1st motion shaft bearings are common to 948, 1098 and 1275 (?803 as well?) - 2A3245. The 948 3rd motion shaft bearing is the same as the 1st motion shaft (2A3245), and all 1098/1275 3rd motion shaft bearings are 22A465.

There are shims shown in the BMC Service Parts List for the 1st motion shaft with thicknesses of 0.004", 0.006" and 0.010" and fitted 'as required' between the nut and the bearing, but what would they do?

[David W.]

Those shims go on the outer race, between the bearing and the front cover and rear tailpiece. They serve to keep the bearing in place.

[David W.]

Part number of the backplate.[frame][/frame]

[IslipMinor]

David,

AEG552 is the 1275 backplate. The 948 is 88G226 and the 1098 is 12G275.

[philthehill]

The first motion shaft protruding past the front face of the gearbox bell housing is normal but make sure that the front face of the bell housing is a snug fit against the rear engine plate before fully tightening the bell housing/rear engine plate bolts. If it not a snug fit check and ask yourself why not!!!

[David W.]

I've fitted the plate to the bell housing, and it's a nice fit.
On the smooth cases, the input shaft is flush with the edge of the bell housing. When I saw the shaft protruding that little bit, I thought, Crikey, what next.

[philthehill]

I may be reading this wrong but think there may be crossed wires here David.
What I really meant was that when you come to install or mate the gearbox with the engine that is with flywheel/clutch and rear engine plate already fitted to the engine make sure that the bell housing is a snug fit against the engine back plate before final tightening of the bell housing/engine back plate bolts. If it does not fit snug there will be something wrong.
Placing the engine back plate on its own against the gearbox bell housing will not tell you anything only that the bolt holes will or will not line up.
Happy spannering.