A/T - Charts and Artwork Manual Updates

9216chevy07

Number: 91-223-7A

Section: 7A

Date: MARCH 1991

Corporate Bulletin No.: 177108


Subject:
AUTOMATIC TRANSMISSION CHARTS AND ARTWORK UPDATES


Model and Year:
1991 C/K, R/V, P TRUCKS AND G VAN
WITH 4L80-E/4L80-EHD AUTOMATIC TRANSMISSION


SERVICE UPDATE

BULLETIN COVERS:

HYDRA-MATIC 4L80-E/4L80-EHD Transmission updates occurring after Unit Repair

Manual printing.


LIGHT DUTY TRUCK UNIT REPAIR MANUAL:

Add Notice - Transmission Disassembly Section:
NOTICE: It is not recommended to use air powered tools to disassemble or assemble transmissions/transaxles. Improper bolt torques can contribute to transmission misdiagnosis and repairs. This information, vital to diagnosis, can only be obtained using hand tools.

Add Caution Notice - Torque Converter:
CAUTION: Torque Converter Assembly is in excess of twenty pounds heavier than the 4L60 converter. Use care when removing Torque Converter (1). Personal injury could result.

Add Notice - Pan and Filter Assembly Section:
NOTICE: Gasket (29) is reusable.

Figure 1:

Figure 2:

Change Tool Number - Pump Assembly Section: (Figures 1 & 2)
J 38789 Pump Remover should read J 37789 Pump Remover.

Figure 3:

Sprag Assembly Section - New Chart for Clutch Plate Application:
Direct clutch - corrected piston travel check. (Figure 3)

Figure 4:

Forward Clutch Assembly Section:
Assembly of the forward Clutch Piston - Seal Protector Outer Tool J-21409 should read J-38732 Seal Protector Outer. Now Chart for Clutch Plate Application: Forward Clutch - corrected piston travel check. (Figure 4)





Pump Assembly Section:
Tools Required - J-38789 Pump Installer/Remover should read J-37789 Install or Connect. Use J-37789, not J-38789. (Figure 5)

Control Valve Assembly Section:
Install or Connect - Guide Pin Set J-25025-B should read J-25025-5.

Transmission Assembly Section:
Gear Unit and Output Assemblies - Inspect # 7 Ring Output Speed Sensor Illustration number should read 660.