7691

I read somewhere that effective Oct. 21 1968 a suffix letter was added to the plant build date code to aid in identification of transmission ratios.
P----A = M-20 P----B =M-21 P----C =M-22

My question, is there a way to identify any M-22 transmissions with out taking it apart.(pre 68 or newer)
Trans in question is not in a car. Thanks, CG

CanadaGrant

You seem to have the codes right and it's stamped right on the trans case for identification.
Here is my example: P9R13A
P = Muncie
9 = 1969
R = October
13 = 13th day of the month
A = M20

B would be an M21 and C would be an M22

early shark

I believe the pre 1968 M22' s main case has provision for a fill and drain plugs, whereas the M20 and M21 main case does not.

LT-1 kid

no,not on a pre 68. m-22 have fine spline input, no grooves on the shaft and close ratio straight cut gear set.