1989 PRODUCT DESIGNATION SYSTEM

MODELS: ALL S/T,C/K,R/V TRUCKS AND M,G AND P VANS EQUIPPED WITH HYDRA-MATIC TRANSMISSIONS

The introduction of a designation system for Hydra-matic products that is consistent in defining torque capacity and other features of our products will begin in 1989.

The 1989 and 1990 model years will be transitional years for transmission designations, with publications referencing both the new and previous designations. In the 1991 model year, publications will no longer reference previous designations as changeover to the new designations will be complete.

Phase-in of Product Designation System by Model Year:

1989: THM 400/Hydra-matic 3L8O (dual designation) 1990: Hydra-matic 3L80 * *Previously THM 400 (footnote only) 1991: Hydra-matic 3L80 (changeover complete, no other designation referenced)

SERVICE NOTES:

Hydra-matic Product Designation System

The chart below will be used for all product designations. For example, with the new system, the product designation for the THM 475 will be Hydra-matic 3L80-HD.

HYDRA-MATIC 3 L 80 HD manufacturer's identification Number (No abbrev.) of Speeds: Type: Series: Major Features: 3 T-Transverse Based On E-Electronic 4 L-Longitudinal Relative Controls 5 Plus Torque A-All wheel V (CVT) M-Manual Capacity Drive HD-Heavy Duty

SERVICE NOTES:

Listed below are current Hydra-matic products with their Previous and New Designations

Previous Designations New Designations AUTOMATIC PRODUCTS THM 700-R4 Hydra-matic 4L60 THM400 Hydra-matic 3L80 THM475 Hydra-matic 3L80-HD MANUAL PRODUCTS HM-290 Hydra-matic 5LM60 HM-117 HM-117

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.