Automatic Transmissions

Turbo Hydra-Matic 180C Automatic Transmission

The THM 180C automatic transmission code and transmission serial number appear on a metal tag fastened to the left side of the transmission just rearward of the converter housing.

Turbo Hydra-Matic 200C Automatic Transmission

The production code number contains the model year, vehicle application and build date code. The transmission model number and sequence number is stamped below the build date code on an identification plate, located on the right side of the transmission case.

EXAMPLE:

83 0 201

1983 Model Year Vehicle Build Code
Application Code Code

In addition to the vehicle application and Julian build date code, Hydra-Matic Division also includes the model year, model and sequence number.

EXAMPLE:

83 CO 6697

1983 Model Year Chevrolet & Vehicle Sequence No.
Application Code


BUILD DATE

The build date code starts with the Julian date (day of the year) on which 1983 production started. The build date code continues with the Julian date until December 31st (365).


Turbo Hydra-Matic 250C and 350C Automatic Transmissions

THM 250C and 350C transmissions produced by Chevrolet Parma and THM 350C transmission produced by Buick Motor Division have the production code stamped on the governor cover.

EXAMPLE:


B 3 D 10 D

MODEL MONTH DAY SHIFT
SOURCE CODE YEAR PRODUCED PRODUCED PRODUCED

B = Parma (THM 250C) 1983 A = Jan. 10th Day D= 1st
B = Parma (THM 350C) B = Feb. N= 2nd
C = March
D = April
E = May
H = June
K = July
M = Aug.
P = Sept.
R = Oct.
S = Nov.
T = Dec.


THM 350C Transmission (Buick)


EXAMPLE:


JD 222 D 83


Vehicle Application Build Date Shift Year
D = 1st 1983
N = 2nd


The 700-R4 transmission produced by Chevrolet Toledo has a production code stamped on the right rear side of the pan rail.


EXAMPLE:


3 TA 222 D

Model Year 1983 Vehicle Application Build Date Shift
D= 1st
N= 2nd