C,K,P, R AND V TRUCKS G-VAN, D-CAR
A THM 400/475/HYDRA-MATIC 3L80/3L80-HD Product Update Book that summarizes product changes made during 1974 through 1988 model years.
The purpose of this book is to provide, in a convenient form, information on how to service a 1974-1988 THM 400/475/HYDRA-MATIC 3L80/3L80-HD transmission based on parts that have been changed. This book can help you to satisfy your customers and prevent a comeback caused by putting in the wrong part.
Hydra-matic Division of General Motors will be distributing the THM 400/475/HYDRA-MATIC 3L80/3L80-HD Product Update Book directly to dealerships.
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.