The 4 Speed Muncie

Here is an exploded view of the 4 speed muncie. You may click the image to see it full size or print it to keep as a shop reference. Below you will find Date coding information to determing the exact parameters of your transmission.

MUNCIE 4 SPEED

DATE CODE

A=JAN
B=FEB
C=MAR
D=APR
E=MAY
H=JUN
K=JUL
M=AUG
P=SEP
R=OCT
S=NOV
T=DEC

*A suffix was added in late 1969 to indicate the model of the transmission.

A=M20 B=M21 C=M22

PRODUCTION DATE CODE

1963-1964
Stampted on pad next to side cover.

1965
Is located on the right side near the mid platge

1966-1974
Are usually found on the right side in raised lettering.

.

EXAMPLE

1963-1966 P1129

(11)NOV (29)29TH DAY 1967-1974 P8S29=(8)YEAR (S)NOV (29)29TH DAY

With Suffix
1969-1974 P0S29C=(70)YEAR (S)NOV (29)29TH DAY (C)M22

VIN NUMBER

1963-1965
Normaly left of case, but a few appear on the top.

1966-1967
Normally on thr right of case, but again some appear on top.

1968-1974
These are located on the rigth side of the case near the top.

RATIOS

YEAR M# RATIO INPUT/SPLINE/TEETH INPUT RINGS CLUSTER/TEETH OUTPUT SHAFT SPLINE

1963-1965 M20 2.56:1 10 24 0 29/22/19/17 27

1966-1970 M20 2.52:1 10 21 2 25/22/19/17 27

1970-1974 M20 2.52:1 26 21 2 25/22/19/17 32

1963-1970 M21 2.20:1 10 26 1 27/22/19/17 27

1970-1974 M21 2.20:1 26 26 1 27/22/19/17 32

1965-1970 M22 2.20:1 10 26 0 27/22/19/17 27

1970-1974 M22 2.20:1 26 26 0 27/22/19/17 32

NOTE: 1963-1969 HAVE 27 SPLINE OUTPUT: 1970-1974 HAVE 32 SPLINE OUTPUT: 1970: THERE

ARE SOME 1970 TRANSMISSIONS WITH BOTH 10 AND 26 SPLINES ON THE INPUT.

TRANSMISSION ASSEMBLIES

YEAR CASE # TAIL # SIDECOVER # SHIFT SHAFT THREAD

1963 3831704 3831731 3831707 5/16TH STUD

1964 3851325 3846429* 3831707 5/16TH STUD

1965 3851325 3857584 3831707 3/8TH STUD

1966 3885010 3857584 3884685 3/8TH STUD

1967 3885010 3857584 3884685 3/8TH STUD

1968 3925660 3857584 3884685 3/8TH STUD

1969 3925660 3857584 3950306 3/8TH THREADED

1970 3925660/3925661 3978764 3952648 3/8TH THREADED

1971 3925661 3978764 3952648 3/8TH THREADED

1972 3925661 3978764 3952648 3/8TH THREADED

1973 3925661 3978764 335308 3/8TH THREADED

1974 3925661 3978764 335308 3/8TH THREADED

NOTE: THERE ARE SOME OTHER CASES, TAILS, AND SIDECOVERS. CALL FOR INFORMATION

ON THESE ODD NUMBERS.

*PONTIAC USED THE 429 TAIL THRU 1969