Automatic Transmission 6T70/75/80 Gen2 Tech Guide 9-2012

PREFACE

The Hydra-matic 6T70/75/80 – Gen 2 Technician’s Guide is intended for automotive technicians that are familiar with the operation of an automatic

transmission. Technicians or other persons not having automatic transmission know-how may find this publication somewhat technically complex if

additional instruction is not provided. Since the intent of this book is to explain the fundamental mechanical, hydraulic and electrical operating principles, technical terms used herein are specific to the transmission industry. However, words commonly associated with the specific transmission function have been defined in a Glossary rather than within the text of this book.

The Hydra-matic 6T70/75/80 – Gen 2 Technician’s Guide is also intended to assist technicians during the service, diagnosis and repair of this transmission.

However, this book is not intended to be a substitute for other General Motors service publications that are normally used on the job. Since there is a wide range of repair procedures and technical specifications specific to certain vehicles and transmission models, the proper service publication must be referred to when servicing the Hydra-matic 6T70/75/80 – Gen 2 transmission.

 

CONTENTS

INTRODUCTION.......................................................................................................... 3

HOW TO USE THIS BOOK .......................................................................................... 4

UNDERSTANDING THE GRAPHICS .......................................................................... 6

TRANSMISSION CUTAWAY VIEW (FOLDOUT)......................................................... 8

GENERAL DESCRIPTION .......................................................................................... 9

PRINCIPLES OF OPERATION..................................................................................9A

MAJOR MECHANICAL COMPONENTS (FOLDOUT)..................................... 10

RANGE REFERENCE CHART......................................................................... 11

TORQUE CONVERTER.................................................................................... 12

APPLY COMPONENTS .................................................................................... 15

PLANETARY GEARSETS ................................................................................ 22

HYDRAULIC CONTROL COMPONENTS ........................................................ 27

ELECTRICAL COMPONENTS......................................................................... 37

POWER FLOW........................................................................................................... 47

COMPLETE HYDRAULIC CIRCUITS...................................................................... 101

LUBRICATION POINTS........................................................................................... 126

BUSHING, BEARING AND WASHER LOCATIONS ............................................... 127

SEAL LOCATIONS.................................................................................................. 128

ILLUSTRATED PARTS LIST ................................................................................... 131

BASIC SPECIFICATIONS........................................................................................ 146

PRODUCT DESIGNATION SYSTEM ...................................................................... 147

GLOSSARY.............................................................................................................. 148

ABBREVIATIONS.................................................................................................... 150

INDEX....................................................................................................................... 151

INTRODUCTION

The Hydra-matic 6T70/75/80 – Gen 2 Technician’s Guide is another Powertrain publication from the

Technician’s Guide series of books. The purpose of this publication, as is the case with other Technician’s Guides, is to provide complete information on the theoretical operating characteristics of this transmission. Operational theories of the mechanical, hydraulic and electrical components are presented in a sequential and functional order to better explain their operation as part of the system.