How to determine a Muncie-22 Transmission

[Ricochett]

Base on my Maincase Casting number ( 3925660 ) from what i have found
this is indicating that my transmission on my 1969 Big block corvette is
a M-22 is there any other why of determining this??? thanxs

 

[Mac]

Base on my Maincase Casting number ( 3925660 ) from what i have found
this is indicating that my transmission on my 1969 Big block corvette is
a M-22 is there any other why of determining this??? thanxs

You're starting off the right way with the casting number. Here's a link on the rest of the steps...

Muncie 4 Speed Transmissions

-Mac

 

[Ricochett]

M-22 trans

Mac
Thanxs for the info

 

[6880 Mike]

M22s are coded C. There were only 101 of them for 1969.

 

[JohnZ]

Base on my Maincase Casting number ( 3925660 ) from what i have found
this is indicating that my transmission on my 1969 Big block corvette is
a M-22 is there any other why of determining this??? thanxs

ALL '68-'69 Muncies had the 3925660 main case, and only those built after October 15, 1968 had the A, B, or C suffix letter on the Muncie "P"-code (A = M20, B = M21, C = M22). The only way (other than the loud whine in 1st, 2nd and 3rd gear) to confirm an M22 is to pull the side cover and look at the helix angle of the gears; the M20/21 gears (left photo) are about 39*, and the M22 gears (right photo) are about 21*.

 

[Hib Halverson]

As usual "JohnZ" is spot-on.

A number of years ago, i did some reasearch into Muncies in general and one thing I learned was that since the last M22 was built in the early, 70s and so few of them were built, there are tons of stuff out there that's at best "misidentified".

The only way to be sure you've got a '22, is to pull the side cover and look at the helix angles.

In fact, when I was doing this research, I use to carry around an M22 gear and when I was shown a trans that was said to be an "M22", I'd have them pull the cover so I could see if my gear matched.

Being that the engine in your car is a low-performance Big-Block, I'd think it unlikely it came stock with a '22. If it really is a Rock Crusher, then it had to have been installed sometime later. It could also be that you believe it might be an M22 but it really is not.

Only way to know for sure?

Like "JohnZ" says...pull the cover and look at the helix angle.

 

[Ricochett]

The outcome of the Muncie-22 Transmission

Well i crawled back under the car today in hope of having 1 of the rarest trans
but i found some good and bad news! the bad news it wasnt a m-22 but the good
news it is a number match trans which i guess it is a real good thing! Based on what ya'll were saying i think i have the Muncie-20 trans the numbers are P9A29(A)meaning M-20)
and the other set of numbers were 19S715455 which match my motor as well as my vin
Thanxs for ya'lls help