Oil Pump Disassembly & Reassembly: Inspection

Check body clearance of driven gear. Push gear to one side of body. Measure body clearance. See Figure. Clearance should be .0028-.0059" (.070-.150 mm). Maximum clearance is .012" (.30 mm). If worn beyond specification, replace pump body.
Check tip clearance of driven gear. Measure between gear teeth and crescent-shaped part of pump body. See Figure. Tip clearance should be .0043-.0055" (.110-.140 mm). Maximum tip clearance is .012" (.30 mm). If tip clearance is greater than maximum specification, replace pump body.

Using a steel straightedge and feeler gauge, measure side clearance of both gears. See Figure. Clearance should be .0008-.0020" (.020-.050 mm). Maximum side clearance is .004" (.10 mm). If worn beyond specification, replace pump body. Drive and driven gears are available in different thicknesses. See OIL PUMP DRIVE & DRIVEN GEAR SPECIFICATIONS table.

OIL PUMP DRIVE & DRIVEN GEAR SPECIFICATIONS

ID Mark		Thickness - In. (mm)
A-540E & A-541E
A		.3717-.3723 (9.440-9.456)
B		.3723-.3730 (9.456-9.474)
C		.3730-.3736 (9.474-9.490)
A-540H
F		.4209-.4212 (10.690-10.699)
G		.4213-.4216 (10.700-10.709)
H		.4217-.4220 (10.710-10.720)
J		.4221-.4224 (10.721-10.730)
K		.4225-.4228 (10.731-10.740)

Measure inside diameter of oil pump body bushing. Maximum inside diameter is 1.503" (38.18 mm). If inside diameter is greater than maximum specification, replace oil pump body. Measure inside diameter of stator shaft bushing. Maximum diameter of stator shaft bushing is .849" (21.57 mm). If worn beyond specification, replace stator shaft.