Pump, Engine Oil: Inspection: Inspection

Disassemble and inspect the oil pump as follows: 

Fig 1: Oil Pump Back Plate, Gerotor & Gerotor Planetary

Courtesy of CHRYSLER GROUP, LLC

1. Visually inspect the lube pump gears for chips, cracks or excessive wear.
2. Remove the back plate (1).
3. Mark TOP on the gerotor planetary (3) using a felt tip pen.
4. Remove the gerotor planetary (3) inspect for excessive wear or damage. Inspect the pump housing and gerotor drive (2) for damaged and excessive wear.
   Fig 2: Measuring Tip Clearance

   Courtesy of CHRYSLER GROUP, LLC

   1 - FEELER GAUGE

5. Install the gerotor planetary in the original position.
6. Measure the tip clearance (1). Maximum clearance is 0.178 mm (0.007 inch). If the oil pump is out of limits, replace the pump.
   Fig 3: Measuring Gerotor To Port Plate Clearance

   Courtesy of CHRYSLER GROUP, LLC

   1 - PORT PLATE

   2 - GEROTOR

7. Measure the clearance of the gerotor drive/gerotor planetary (2) to port plate (1). Maximum clearance is 0.127 mm (0.005 inch). If the oil pump is out of limits, replace the pump.
   Fig 4: Measuring Gerotor Planetary To Body Bore Clearance

   Courtesy of CHRYSLER GROUP, LLC

   1 - BODY BORE

   2 - GEROTOR PLANETARY

8. Measure the clearance of the gerotor planetary to the body bore (1). Maximum clearance is 0.381 mm (0.015 inch). If the oil pump is out of limits, replace the pump.
   Fig 5: Measure Gear Backlash

   Courtesy of CHRYSLER GROUP, LLC

   1 - OIL PUMP DRIVE GEAR

   2 - IDLER GEAR

   3 - BACKLASH

   4 - BACKLASH

9. Measure the gears backlash (3, 4). The limits of a used pump is 0.15 - 0.25 mm (0.006 - 0.010 inch). If the backlash is out of limits, replace the oil pump.
10. Install the back plate.