Oil Pump Cleaning and Inspection
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Remove the oil pump gear cover bolts.
- Remove the oil pump gear cover.
- Use a feeler gauge to measure the clearance between the gear teeth and the oil pump housing. The production clearance is 0.125-0.221 mm (0.0049-0.0087 in) and the service limit is 0.221 mm (0.0087 in).
- Replace the oil pump assembly if the clearance exceeds the service limit.
- Use a feeler gauge and a straightedge to measure the clearance between the side of the gear and the cover. The production clearance is 0.064-0.109 mm (0.0025-0.0043 in) and the service limit is 0.109 mm (0.0043 in).
- Replace the oil pump assembly if the clearance exceeds the service limit.
- Calculate the driven gear shaft to bushing clearance.
- Measure the driven gear shaft outside diameter. The production specification is 19.947-19.960 mm (0.7853-0.7858 in) and the service limit is 19.86 mm (0.7819 in).
- Measure the driven gear bushing inside diameter. The production value is 20 mm (0.7874 in).
- Calculate the driven gear shaft to bushing clearance. The service limit is 0.14 mm (0.0055 in)
- Replace the oil pump assembly if the clearance exceeds the service limit.
- Install the oil pump gear cover to the oil pump assembly.
- Install the oil pump gear cover bolts.
Tighten: Tighten the oil pump gear cover bolts to 21 N.m (15 lb ft).
NOTE:
Refer to Fastener Notice in Cautions and Notices.