Chevrolet Silverado / GMC Sierra. Manual - part 902
Fig. 212: Measuring Drive Gear Side Clearance
Courtesy of GENERAL MOTORS CORP.
9. Hold a straight edge across the oil pump body (1) and the drive gear (3). Measure the
clearance between the drive gear and the straight edge. This is the drive gear side clearance.
Specification: The drive gear maximum side clearance is 0.066 mm (0.0026 in).
10. Hold a straight edge across the oil pump body (1) and the driven gear (2). Measure the
clearance between the driven gear and the straight edge.
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Automatic Transmission - Allison - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
Specification: The driven gear maximum side clearance is 0.050 mm (0.0022 in).
Fig. 213: Drive Gear & Driven Gears
Courtesy of GENERAL MOTORS CORP.
11. Remove the drive gear (1) and driven gear (2) from the oil pump body (3).
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Automatic Transmission - Allison - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
Oil Pump Wear Plate Inspection
Fig. 214: Checking Wear Plate Thickness
Courtesy of GENERAL MOTORS CORP.
1. Inspect the wear plate (1) for damage. The wear plate must not be scored, nicked, or
grooved.
2. Measure the thickness of the wear plate in the gear wear area.
IMPORTANT: Replace the oil pump wear plate if specifications are not met.
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Automatic Transmission - Allison - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
Specification: The thickness of the wear plate must not be less than 2.950 mm (0.116 in).
OIL PUMP BODY BUSHING REPLACEMENT
Tools Required
J 43771 Pump Bushing Removal and Installation Tool. See Special Tools.
J 8092 Universal Driver
Replacement
Fig. 215: Inspecting Oil Pump Bushing Diameter
Courtesy of GENERAL MOTORS CORP.
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Automatic Transmission - Allison - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado