Muncie decoding
Thread Starter
Intermediate
Joined: Mar 2009
Posts: 28
Likes: 0
From: Aguadilla PR
Muncie decoding
Need help decoding this trans, I've looked references but info is not helping including some web sites and Colvin, here the info:
4-Speed
Housing 3925660
Tail 3857584
Tag 7M110896
7 bolt cover
Stamp: POP25B, decodes as Muncie September 25, 1970 with M21 gear?
but it is a 660 casting with drain plug and gee it makes a lot on whining in 1st, 2nd and 3rd but not in 4th.
4-Speed
Housing 3925660
Tail 3857584
Tag 7M110896
7 bolt cover
Stamp: POP25B, decodes as Muncie September 25, 1970 with M21 gear?
but it is a 660 casting with drain plug and gee it makes a lot on whining in 1st, 2nd and 3rd but not in 4th.
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,926
From: Washington Michigan
POP25B says it was made in September '69 for the '70 model year as an M21. The 7M VIN stamp says it was originally installed in an Olds Cutlass built in Lansing, Michigan, but the "7" is for the '67 model year - sure the "7" isn't a "9"?
Pull the side cover off and see which helix angle the gears have - if it looks like the one on the left, it's an M20 or M21; if it looks like the one on the right, it's an M22.
Pull the side cover off and see which helix angle the gears have - if it looks like the one on the left, it's an M20 or M21; if it looks like the one on the right, it's an M22.
Burning Brakes
Joined: Aug 2001
Posts: 1,104
Likes: 1
From: Frederick Md
All the late muncies had the 660 case.
Need help decoding this trans, I've looked references but info is not helping including some web sites and Colvin, here the info:
4-Speed
Housing 3925660
Tail 3857584
Tag 7M110896
7 bolt cover
Stamp: POP25B, decodes as Muncie September 25, 1970 with M21 gear?
but it is a 660 casting with drain plug and gee it makes a lot on whining in 1st, 2nd and 3rd but not in 4th.
4-Speed
Housing 3925660
Tail 3857584
Tag 7M110896
7 bolt cover
Stamp: POP25B, decodes as Muncie September 25, 1970 with M21 gear?
but it is a 660 casting with drain plug and gee it makes a lot on whining in 1st, 2nd and 3rd but not in 4th.
Thread Starter
Intermediate
Joined: Mar 2009
Posts: 28
Likes: 0
From: Aguadilla PR
it is a 7. The other point is, given it is so hard to find a working borg warner T10-7A for a 58 vette, would the M21/M22 perception of having a stronger or hi-performance muncie transmission replacement better than having the original and correct butter strengh T10? Perception I mean value of the car. Some people say "heck with originality" as far as transmission is concerned.
