A/T - 4L60/700-R4 Shift Speed and Line Pressure Charts
89chevy34Number: 91-01-7A
Section: 7A
Date: November 1989
Corporate Bulletin No.: 977151
Subject: 1991 MODEL EARLY INTRODUCTION - SHIFT SPEED AND LINE PRESSURE CHARTS
Model and Year: 1991 B, F CARS AND M VAN WITH 4L60/700-R4 AUTOMATIC TRANSMISSION
Figure 1:
Figure 2:
Figure 3:
TO: ALL CHEVROLET DEALERS
This bulletin covers early introduction of 1991 HYDRA-MATIC 4L60 transmission models (Figure 1). Some 1991 vehicles scheduled for production in early 1990 will contain 1991 model year transmissions. This bulletin contains shift speed and line pressure charts for use in diagnosing these transmission models (Figures 2 and 3).
This information is not yet contained in any service manual. Please use these charts until the 1991 service manual is published.