Chevrolet Silverado / GMC Sierra. Service manual — part 904

Fig. 218: Using J 43779 To Install Locating Pins To Specified Height
Courtesy of GENERAL MOTORS CORP.

IMPORTANT: Do not replace the oil pump locating pin or pins unless the

pin or pins are damaged.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - Allison - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

1. Remove the locating pin (2) from the oil pump body (3).

2. Using J 43779 (1), install the locating pin (2) to the specified height. See Special Tools.

Specification: The locating pin installed height measurement is 10.7-11.3 mm (0.42-0.44
in) above the oil pump body surface.

OIL PUMP ASSEMBLE

NOTE:

DO NOT mar the oil pump body surface when installing the
locating pin(s). Tap gently on the locating pin installer tool.
Heavy or continued hammering will damage the oil pump body
surface.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - Allison - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

Fig. 219: Exploded View Of Oil Pump
Courtesy of GENERAL MOTORS CORP.

1. Install the O-ring (6) onto the oil pump body (4).

2. Position the oil pump body (4) on the work table so that the oil pump body hub is facing

down.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - Allison - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

3. Lubricate the oil pump drive gear (2) and driven gear (3).

4. Align the drive gear (2) and driven gear (3) with the oil pump so that the punch marks are in

the same position as when they were originally removed.

5. Install the gears into the oil pump body (4).

6. Align the locating pin holes in the wear plate (1) with the locating pins (5) in the oil pump

body. Ensure the bolt holes in the pump wear plate (1) align with the bolt holes on the oil
pump body (4).

7. Install the wear plate (1) onto the locating pins (5) and the oil pump body (4).

TRANSMISSION FLUID PUMP COVER DISASSEMBLE

Tools Required

J 24459-5 Spring Compressor Adapter. See Special Tools.

J 43770 Main Lube, Converter Relief Valve Spring Compressor. See Special Tools.

J 43773 Valve Spring Compressor. See Special Tools.

Disassemble

NOTE:

When the drive gear and driven gear are installed into the oil
pump, the gears must be installed in their original orientation
by having their punch marks in the same position as when they
were originally removed. Failure to install the drive and driven
gears in their original orientation may damage the
transmission.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - Allison - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado