Can anybody help in ID'ing this 4-speed?

Details include:
1. Aluminum case.
2. 26 spline input shaft
3. 3925661 is stamped on the main case
4. 3978764 is stamped on the rear cae.

Thanks!

Denny K

dennykronz@hotmail.com

Need a little more info....
There is a number on the mid plate starting with a P
for example: P1D12A
P = Muncie
1 = Year (1971)
D = April
12 = day of month
A = M-20 B = M-21 C = M-22
That number will give the month, day, yr, as well as the ratio...
So far, you have a 71-74 Muncie...

Thanks ZMan for your response!!!

I looked at the tranny again and could find no numbers on the mid plate. (I assume you are referring to the 1/2" thick piece between the main case and the tailshaft case?)

I did find this additional info:

Metal Tag on one of the bolts that fastens the shifter fork plate - 3981710WY

Stamping on rear of main case / adjacent to midplate running vertically up the casing
CCO 44233
Does this provide any additional clues??

Thanks!!

DennyK

Hi Denny,
No, unfortunately, those numbers aren't much help.
The "P" number I refered to, is what we need.
Not 100% sure if it's actually on the mid plate, but it is in the area between the main case, and the tail housing.
Are there any "rings" around the input shaft?
2 rings = M-20, 1 ring = M-21

The CC0 44233 indicates a replacement case:

CC = replacement case
0 = 1970
44233 = case sequence number

Dave

Gentlemen:

The input shaft has 1 ring.

Thanks for all your help.

DennyK

Hey David,
Thanks...I didn't know that.
Denny, 1 ring = Close Ratio M-21.
Sounds like you have yourself a nice trans there graemlins/thumbsup.gif