mg gearbox

[mark beson]

hi, i have an mg midget 1275cc which i think may have a morris gear box, i got a new 1st motion shaft bearing from an mg dealer bot it looks the same but wont slide on, can anyone help in letting mr know what i need, it looks so similar it looks like a slight machining error but have been assured this isnot the case. cheers..

[mike.perry]

The MG 1275 box has a reversing light switch at the bottom of the gear selector, the 1098 Morris box has not.
Also I believe the gears are cut differently and the boxes use different bearings.

[bmcecosse]

I would be surprised if the bearings are different. There were some differences in the internal bearings under the gears - but not with the main shaft bearings. Can you not measure the shaft - and the bearing?? And compare the markings/numbers of the two bearings.

[daveyl]

I'm sure I saw on this site a list of serial numbers that were unique to the midget gear box and was a sure way of identifying the midge box.
I can't find it though! Anyone?

[IslipMinor]

Apart from the very early Frogeyes, all the other Sprites and Midget gearboxes had different ratios to the equivalent MInor/A35 etc. The primary or first motion shaft is different, as is the laygear cluster and also the mainshaft gears as they run on needle roller bearings, instead of the bronze bushes for the Minor. The basic shaft bearings are common.

Just to add a complication there were 2 sets of gear profiles in the 1275 'box, 'A' and 'B', and they are not interchangeable!

As a first check can you work out the ratios in the box that you have? That way we can establish if it is Minor or Spridget.

[bmcecosse]

But whatever the ratios - the main bearing should fit - if it's the right bearing!

[les]

Do a search, a few months ago I listed all the relevent data for the 1275 midget box, this may help you. The first motion shaft for the 1275 midget has 22g229 marked on the shaft, and has 20 teeth.