PUMP GP-GEAR 2085478 - Caterpillar

If any part of the engine oil pump is worn enough in order to affect the performance of the engine oil pump, the engine oil pump must be replaced.Perform the following procedures in order to inspect the engine oil pump. Refer to Specifications, "Engine Oil Pump".
Illustration 1 g00458938
Idler gear and components of the engine oil pump
(1) C-clip
(2) Collar
(3) Spring
(4) Shim
(5) Oil pump cover
(6) Inner rotor
(7) Spring
(8) Outer rotor
(9) Bushing
(10) Idler gear
(11) Thrust washer
Remove the front housing. Remove C-clip (1). Note: If the front housing is removed, do not turn the crankshaft.
Disassemble the engine oil pump. Refer to Disassembly and Assembly, "Engine Oil Pump - Remove" for additional information. Do not remove bushing (9) from idler gear (10) unless damage is observed.
Clean all of the parts and inspect the parts for cracks in the metal or other damage. Look for wear on the components. Ensure that bushing (9) is not loose in idler gear (10).
Illustration 2 g00459701
Clearance between the inner rotor and the outer rotor
Install the idler gear and the inner rotor on the shaft. Measure clearance (A) between inner rotor (6) and outer rotor (8). Refer to Specifications, "Engine Oil Pump".
Illustration 3 g01290817
Face of the cover for the oil pump above the face of the idler gear
(1) C-clip
(2) Collar
(4) Shim
(12) Feeler gauge
Use feeler gauge (12) to measure the distance between C-clip (1) and collar (2).
When the components of the engine oil pump are installed on the front housing, measurement (B) between C-clip (1) and collar (2) must be between 0.10 to 0.15 mm (0.004 to 0.006 inch)for new components. Dimension B must be not more than 0.20 mm (0.008 inch) for used parts. The distance between the faces is adjusted with shims (4). The thicknesses of the shims are given in Specifications, "Engine Oil Pump".
Illustration 4 g00826185
Install the components of the engine oil pump and the front housing on the cylinder block. Make sure that the two dowels align with the bushing, the outer rotor, and the holes in the idler gear. Align the timing mark (15) on idler gear (10) with the timing mark on crankshaft gear (16) when you install the idler gear on the oil pump shaft. Also, align the other timing mark (15) on idler gear (10) with the timing mark on the camshaft gear (13). The hole (14) in oil pump cover (5) should align with the locating pin in the front housing.Note: When the front housing is not installed on the engine, do not rotate the crankshaft.