|
TRANSMISSION IDENTIFICATION
The transmission identification code will differ depending the type of
transmission - Manual, Powerglide, Turbo Hydra-Matic 350 or Turbo Hydra-Matic 400.
The manual and Powerglide will have a production
code consisting of a prefix letter designating the assembly plant, a
production date (year/month letter/day number) and a shift code for
day or night shift if the assembly plant was using two shifts.
The Turbo Hydra-Matic 350 and 400 used a different date
coding format. This production code consists
of a single-digit model year (2) followed by an engine/model code letter
and a three-digit production date. The three-digit production
date begins with the first day of January, 1970. For example, a production
date of 298 would be October 25, 1970 or, the 298th day of the 1970
calendar year. January 1 of
1971 would be 366.
A Julian
date calendar can be found here to assist you. Remember, a production
date of 001 to 365 is calendar year 1970 and 366 or higher is
calendar
year 1971. If the production date is over 365, subtract 365 and find
the corresponding Julian date for 1971. It's not known when the last
TH400 was installed in a 1971 Chevelle, but assuming July 31 the last
model build day, a date of 577 should be the largest date. July 31,
1971 (577) is the 212th day of 1971. Subtracting 365 from 577
gives you 212 - July 31, 1971.
| Manual and Powerglide Transmission Designations |
| 3-speed |
4-speed |
Powerglide |
D - Saginaw (3-speed w/overdrive) **
O - Saginaw (3-speed w/overdrive) **
M - Muncie
K - McKinnon Industries
S - Saginaw
W - Warner Gear |
N - Muncie
*P - Muncie
R - Saginaw |
C - Cleveland
E - McKinnon Industries
T - Toledo
|
| A typical Muncie
will break down as follows: P2A01C breaks down to P
(Muncie), 2 (1972 model year), A (January), 01 (day), C (M22). Any Muncie
build in calendar year 1971
for an August through December built 1972
model year would be dated
with M through T (August through December) such as P2R25A meaning
the transmission was coded for a 1972 model year Chevelle on
October 25, (calendar year) 1971. The letter suffix code
identifies the M20, M21, and M22; "A" for the M20, "B" for the M21,
or "C" for the M22. |
| Year - 2 |
|
|
| Calendar Month |
| M - August |
P - September |
R - October |
| S - November |
T - December |
A - January |
| B - February |
C - March |
D - April |
| *E - May |
H - June |
K - July |
| |
|
|
Day Number
1...31 |
| |
|
|
Powerglide 2-speed and Turbo Hydra-Matic 3-speed
Automatic Transmission
B - Cleveland (TH350)
C - Cleveland (PG) only available with the base 6-cyl and V8
engines.
Y - Toledo (TH350)
Variations have been found for Powerglide and TH350 transmission
designations. Normal code would be the plant letter, model year,
month/day such as B2C14 for Cleveland (B), 1972 (2) March 14 (C14).
A Turbo Hydra-Matic 350 would be coded like Y2E01 for Toledo
(Y), 1972 (2), May 1 (E01). |
|
Turbo Hydra-Matic 400 Transmission
Designations
A sample TH400 code would be 2D275 where 2 is model year 1972, D
designates engine code/402~240hp, and 275 is the 275th day of
calendar year 1971, October 2nd.
|
|