A/T IDENTIFICATION ALL THM TRANSMISSIONS

ALL LIGHT DUTY MODELS WITH AUTOMATIC TRANSMISSIONS

This information is being published to assist the technicians in the field in properly identifying the transmission identification (I.D.), its meaning and where it is located on the transmission. Therefore, this bulletin will explain these items for currently manufactured THM automatic transmissions.

The transmission identification tag or stamped identificaiton identifies such information as the transmission type, model year, mode, serial number, Julian date, etc.

Notice Anytime assistance is needed concerning a transmission condition, the technician must have the following information at the time the inquiry is made the transmission type, model year, serial number, Julian date, etc.

Refer to the following information and illustrations, which will explain all transmission identifications.

Explanation of all Key Transmission Identifications

Model Year Tells what model year the transmission was built. Model: Transmission model identification. Julian Date: Tells what day of the year the transmission was built. It is also very important to remember that the transmission model year starts MID YEAR. This means that the first transmission built in any model year will start with a higher Julian date.

EXAMPLE: IF THE FIRST TRANSMISSION IN 1984 WAS BUILT ON AUGUST 5, THEN THE JULIAN DATE STARTS AT 218 AND GOES TO 365 (DECEMBER 31) THE JULIAN DATE WILL THEN DROP TO 001 JANUARY 1, AND THEN CONTINUE TO 217 (AUGUST 4, 1985).

SERIAL NUMBER: Tells what sequence the transmission was built.

SHIFT BUILT: Tells what shift the transmission was built.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.