M type/ Minor differentials

[sv4670]

Can someone tell me are Minor and M type differential assemblies interchangeable and what are the final drive ratios?
I am wondering about fitting a lower ratio as the car will be used for trials. I see four star diffs are availabe for MMM MGs, will they fit a M type?
All advice gratefully received

[Ian Grace]

Happy New Year Derek.

For trials, I'd go for a 7/37 - lower ratio and stronger pinion because it had fatter teeth. But remember Ronald Trumpi over in Holland is searching for one of these too.

Ian

[sv4670]

Thanks Ian and happy New Year to you too!

The chap I bought my car from has stacks of Minr bits rusting in the back of his barn. I might be able to get a diff from him. Is it possible to tell the ratio without taking the assembly out of the axle casing - is the ratio stamped on the casting or something?

It occured to me that the diff from a modern vehicle might fit - a little Suzuki pick up truck or similar. My justification for this is to preserve the original M type diff. I understand MG Y type diffs can be made to fit without much of problem and they have a four star diff. Probably not so easy to find though.

[garagiste]

From memory the numbers are stamped on the top of the aluminium nose.

However BEWARE all the carriers are similar and the innards could differ from the ratio shown on the housing.

Is it not possible to check the ratio by counting the number of turns of the input and those of the half shaft?

[peterb]

!934 saloon diff. Number stamped on aluminium casting: 8/43
I believe other ratios used were 6/33 and 7/37

[Sam Christie]

I wonder what the 'S' signifies in the case.

[Simon]

Does anyone know which vehicle the 6 / 33 ratio was used on.

[Ian Grace]

Sam,

No idea what the S stands for, but doesn't the dip stick make this a Morris 8 (or similar) diff.?

Can't be categorical, but not sure any Minors/M Types had diff. dipsticks.

[Sam Christie]

Indeed I believe it is a Morris 8 diff. I understand it will fit a Minor/M-type axle which is why I have it in reserve.

[Ian Grace]

As my old drill Sergeant used to say, while brandishing his pace stick somewhat menacingly, "It WILL fit"!

[sv4670]

Thanks for the advice, I wonder what other diffs will fit. I have a modern Morris Minor diff somehwere in the garage. I may see if that can be made to fit this weekend if I have a minute - need to get the other car ready for the Measham rally though.

[sv4670]

Just acquired a 9/44 ratio diff. The casing is stamped with a large letter M. Did M type diffs have this rather than the ratio stamped on?