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MG Midget and Sprite Technical - Gearbox identification

Hi
I'm searching for a MG midget 1275 gearbox but becoming confused with the Morris Minor gearbox which is very similar.
I have found a gearbox with the following information, can you tell me if it is a MG or Minor gearbox please.

Remote housing 22A480
Engine case 22A478 VAP10
It also has a round tag on the bellhousing with TYPE 256371 and possibly 38G27 under the tag which is rivited on.

The box doesn't appear to have the reversing switch so the remote housing could have been changed.

I'm stumped, hope you can assist me.

Regards

Dermot Murray
Dermot Murray

If it has a 22G229 input shaft then I think it’s almost certainly a 1275 Midget box. It’s fairly easy to spot - as long as it’s not bolted up to an engine!
John Payne

Dermot

The Midget box has the number 22G 229 stamped on the input shaft. If its 22G171 its from a Morris Minor. The case numbers are generic for the two types of gearbox. Hope this helps

Bob Beaumont

Dermot

Maybe some useful info in the following archived BBS threads:
http://www.mg-cars.info/mg-midget-sprite-technical-bbs/gearbox-help-identification-2014082711192119974.htm

http://www.mg-cars.net/mg-midget-sprite-technical-bbs/identifying-a-gearbox-2010090222273315193.htm

And from a Morris Minor forum:
https://www.mmoc.org.uk/Messageboard/viewtopic.php?t=29238

Best wishes
Mike


M Wood

As said, you need to see 22G229 on the input or first motion shaft. Smallish lettering, you need to look up close.
Bill Bretherton

This is where the input shaft identification is located. This is actually off a late Morris Minor gearbox.
Rob



MG Moneypit

A 22G1117 input shaft is also 1275 Spridget.
The round plate you mention is an indication that at some time it's been factory reconditioned, they painted the whole 'box gold so you should see some traces.
David Smith

'A 22G1117 input shaft is also 1275 Midget'

That's interesting! I cannot find a reference to this part number in any of the BMC/BL Parts Manuals up to 1977. Googling 22G1117 certainly comes up with it being used on a 1275 gearbox, so where does it come from?

From the BMC/BL Parts Manuals, the 1275 Sprite/Midget box has a first motion shaft part number of 22G229, and this is usually very clearly stamped on the shaft, which is visible though the large hole in the top of the bellhousing.

What part number does yours have?

The attached table shows all the part number variants for the in-line A-Series gearboxes.

Richard



Richard Wale

I think some numbers for the 1275cc box are missing. The gears had two series of numbers. The 2nd/3rd and Laygear are the same as Cooper S 3 synchro boxes. Eg the laygear original part number was 22g232 superceded by 22g1100. The chart only lists 22g1100.
Bob Beaumont

Thanks for the table Richard but I'm wondering if I've got a problem!

I just checked my 1275's input shaft - it' s marked 22G172, which is for the 1098.

I think it's quite an early 1275 as it's 1967 so it could be BMC just using up old stock but it could be a replacement, though I've nothing to say so in its history file.

The table lists a different release bearing.
I've treated it to one of Alan Anstead's roller release bearing. Will it fit or do I need a different one for a 1098 gearbox?

Colin
C Mee

Colin

I thought the 22G172 was for the 1098 and early 1275, with the A-type gears.

The 1098 uses a different release bearing, as the clutch cover is much deeper. Nothing to do with the gearbox.
Dave O'Neill 2

It just got a bit worse!

I just did a double check due to dodgy memory - the input shaft is a 22G171 - I've got a blooming Morris 1000 gearbox! :(

C

Edit. Thanks Dave, I've got a 1275 clutch - at least, that's what I paid for!
C Mee

Colin
You have one of my 1275 roller release bearings for use with the 6.5 in diaphragm clutch. A 1098 should be a 7.25 in spring clutch which would need a different type.
Alan


Alan Anstead

Thanks Alan,

After Dave's comment I was pretty sure the bearing would be OK but it's good to have your assurance.

Colin
C Mee

Richard, your table of gearbox data doesn't show what colours they should be!

I'm curious to know whether my Sprite's gearbox would have been painted originally.

The Morris Minor box that it currently possesses had quite a lot of green on it, but in such random places that I assumed it was just over-spray from a PO's engine painting.

While scrolling through used parts sites on the net I've come across plain bare metal ones and others painted green or black - were they ever painted originally, and, if so, what would my '67 Sprite's box have been?

The Minor box is now clean and completely devoid of paint and ready to go back in place as I like the bare metal look. In the mean-time I've tracked down a 22G229 box but it's at the opposite side of the country at the moment and might need a rebuild before I introduce it to the Sprite.

My Sprite's a long way from concours, and a painted gearbox won't make it go any faster but it's one of those silly things that suits my simple mind to get right!

Colin
C Mee

If they could save a few pennies by not painting gearboxes they would and did as I think they should be natural aluminium.
Rob
MG Moneypit

I recall a debate about the colour of ribcase boxes. I have 2 ribcase midget boxes and they are both bare aluminium. One has got a green stripe on it just behind the bell housing. I left mine in the bare metal but the engine is the traditional BMC green.
Bob Beaumont

This thread was discussed between 06/06/2020 and 28/06/2020

MG Midget and Sprite Technical index

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