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m20 and m21

how do you tell the differnce between an m20 and m21 gearbox from the outside
cheers

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boxes

input shafts.
on the front of the spline there are notches cut into it.
1 notch= M20, 2= M21, none = M22

Cheers
John
:o)

Dislike me for who I am you may, like me for whom I'm not, you never will...
MY SHED

M22 was the commercial light

M22 was the commercial light truck aussie box but I heard there was another one used in bigger Bedford trucks that was lower ratio again and supposedly had a beefed up case but I have not seen one??? Urban myth??? If its true can you fit the internals from a m21??

wasn't M22 just the holden

wasn't M22 just the holden code for the muncie they put behind 350 chevs

M22 not Muncie code...

No, it was the same old 'Aussie' box, but with shorter intermediate ratios, than the M20 (passenger 6cyls) and much shorter than the M21 (passenger 8cyls).

'Quick, claim your coolness by spruiking/endorsing/worshipping well-marketed American corporations in an entirely defiant, yet sheep-like manner!'

m 22 muncie

M20 , m21 amd m22 were also codes used for muncie gearboxes . M20 and m21 were a bit like our "aussie 4 speeds " in that the m20 was wide ratio and the m21 was close ratio. the m22 muncie was nicknamed " the rockcrusher " due to its noisy operation in 1/2/3 gears due to less mesh angle on the gears ,meant to make them stronger through less thrust load and less heat buildup . I ran an m22 in my old sports sedan few years back and can vouch for there noisy operation as they sound very agricultural indeed , but I never broke it !

Cheers
JH

Clarification

Ta for the extra details!

'Quick, claim your coolness by spruiking/endorsing/worshipping well-marketed American corporations in an entirely defiant, yet sheep-like manner!'

all the M's

Even the Saginaws used the same codes

Cheers
John
:o)

Dislike me for who I am you may, like me for whom I'm not, you never will...
MY SHED


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