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Home >> Jeep >> 2008 >> Commander Base, 3.7 K, RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 3 (4.7L Engine (Service Information)) >> Lubrication >> Pump - Engine Oil >> Inspection >> Oil Pump

Oil Pump

WARNING: This page is about a different variant/trim than selected.
Fig 1: Checking Oil Pump Cover Flatness
GC0003858Courtesy of CHRYSLER LLC
1 - STRAIGHT EDGE
2 - FEELER GAUGE
3 - OIL PUMP COVER
CAUTION: Oil pump pressure relief valve and spring should not be removed from the oil pump. If these components are disassembled and or removed from the pump the entire oil pump assembly must be replaced.
  1. Clean all parts thoroughly. Mating surface of the oil pump housing should be smooth. If the pump cover is scratched or grooved the oil pump assembly should be replaced.
  2. Lay a straight edge across the pump cover surface (3). If a 0.025 mm (0.001 in.) feeler gauge (2) can be inserted between the cover and the straight edge the oil pump assembly should be replaced.
    Fig 2: Measuring Outer Rotor Thickness
    GC0003859Courtesy of CHRYSLER LLC
  3. Measure the thickness of the outer rotor. If the outer rotor thickness measures at 12.005 mm (0.472 in.) or less the oil pump assembly must be replaced.
  4. Measure the diameter of the outer rotor. If the outer rotor diameter measures at 85.925 mm (3.382 in.) or less the oil pump assembly must be replaced.
    Fig 3: Measuring Inner Rotor Thickness
    GC0003860Courtesy of CHRYSLER LLC
  5. Measure the thickness of the inner rotor. If the inner rotor thickness measures at 12.005 mm (0.472 in.) or less then the oil pump assembly must be replaced.
    Fig 4: Measuring Outer Rotor Clearance
    GC0003861Courtesy of CHRYSLER LLC
    1 - FEELER GAUGE
    2 - OUTER ROTOR
  6. Slide outer rotor (2) into the body of the oil pump. Press the outer rotor to one side of the oil pump body and measure clearance between the outer rotor and the body. If the measurement is 0.235mm (0.009 in.) or more the oil pump assembly must be replaced.
    Fig 5: Measuring Clearance Between Rotors
    GC0003862Courtesy of CHRYSLER LLC
    1 - OUTER ROTOR
    2 - FEELER GAUGE
    3 - INNER ROTOR
  7. Install the inner rotor into the oil pump body. Measure the clearance between the inner (3) and outer (1) rotors. If the clearance between the rotors is.150 mm (0.006 in.) or more the oil pump assembly must be replaced.
    Fig 6: Measuring Flatness Of Rotors
    GC0003863Courtesy of CHRYSLER LLC
    1 - STRAIGHT EDGE
    2 - FEELER GAUGE
  8. Place a straight edge (1) across the body of the oil pump (between the bolt holes), if a feeler gauge (2) of.095 mm (0.0038 in.) or greater can be inserted between the straightedge and the rotors, the pump must be replaced.
NOTE: The 3.7L/4.7L Oil pump is released as an assembly. There are no Daimler Chrysler part numbers for Sub-Assembly components. In the event the oil pump is not functioning or out of specification it must be replaced as an assembly.