Speedometer Ratios on Four Speed Gearboxes

[Sam Christie]

It seems most common for '74' Minor four speed gearboxes to be marked with a 4/17 speedometer ratio but some are marked 3/12. I assume 4/17 is Morris Minor. Is 3/12 associated with the Family Eight?



Are any other speedometer ratios seen on '74' gearboxes ?

[Trevor Wilkinson]

That has just triggered my memory, the 4spd Hornet box in my Minor has 3/12 ratio.
Trevor.

[Sam Christie]

The difference between 3/12 and 4/17 viewed simply as fractions does not seem very significant. Is it possible a change in wheel size might have been a factor?

[Ian Grace]

My 1933 season McEvoy has 3/12, and this must have been standard for the season. So is it that the 4-speed boxes were 3/12 and the 3-speed boxes were 4/17?

But then I guess I should have learned by now that life is never that simple.

[Simon]

Could it be that 33 Minors had 19 inch wheels and 34 Minors had 18 inch wheels.

[Ian Grace]

That is exactly correct.

[Sam Christie]

I assume three speeds are 4/17 (is this marked somewhere?) but as you can see four speeds vary. Right hand example is a synchromesh version. I think the one on the left might be yours Ian (I cannot recall where I found the image).Could it be that the non synchromesh four speed was considered more 'sporty' for the McEvoy ? I have never experienced the synchromesh version but I think it is said to be a bit slower in changing gear. Has anyone experience of both?

[Ian Grace]

Sam,

The syncro box was only available on the Minor for the 1934 season, and that's why my '33 season McEvoy has the 4-speed crash box.

It does look like my box, but I'm in the office and the box is in the garage. I'l check tonight.

[Ian Grace]

Yup - that's my gearbox.