Ram B1500, B2500, B3500, 1999-2003

Oil Pump

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Inspection




NOTE
The oil pump is responsible for providing constant lubrication to the whole engine and so it is recommended that a new oil pump be installed when rebuilding the engine.

  1. Completely disassemble the oil pump and thoroughly clean all of the components. Inspect the oil pump gears and housing for wear and/or damage. Ensure that the pressure relief valve operates properly and there is no binding or sticking due to varnish or debris.
  2.  
  3. Using a micrometer, check dimensions of the pump components against the specifications given. Typical checks include:

    Clearance between rotors
     
    Outer rotor to housing clearance
     
    Inner and outer rotor thickness
     
    Clearance over installed rotors
     
    Cover flatness
     

  4.  
  5. If all of the parts are in proper working condition, lubricate the gears and relief valve, and assemble the pump.
  6.  



Click image to see an enlarged view

Fig. Measuring clearance over installed rotors on a gear-type oil pump

Overhaul




WARNING
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.


WARNING
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.  
  3. Lay a straight edge across the pump cover surface. If a 0.001 in. (0.025mm) feeler gauge can be inserted between the cover and the straight edge the oil pump assembly should be replaced.

    Click image to see an enlarged view

    Fig. Lay a straight edge (1) 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

  4.  
  5. Measure the thickness of the outer rotor. If the outer rotor thickness measures at 0.472 in. (12.005mm) or less the oil pump assembly must be replaced.

    Click image to see an enlarged view

    Fig. Measure the thickness of the outer rotor. If the outer rotor thickness measures at 0.472 in. (12.005mm) or less the oil pump assembly must be replaced

  6.  
  7. Measure the diameter of the outer rotor. If the outer rotor diameter measures at 3.382 in. (85.925mm) or less the oil pump assembly must be replaced.
  8.  
  9. Measure the thickness of the inner rotor. If the inner rotor thickness measures at 0.472 (12.005mm) or less then the oil pump assembly must be replaced.

    Click image to see an enlarged view

    Fig. Measure the diameter of the outer rotor. If the outer rotor diameter measures at 3.382 in. (85.925mm) or less the oil pump assembly must be replaced

  10.  
  11. Slide outer rotor 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 0.009 (0.235mm) or more the oil pump assembly must be replaced.

    Click image to see an enlarged view

    Fig. Slide outer rotor (2) into the body of the oil pump. Press the outer rotor to one side of the oil pump body and use a feeler gauge (1) to 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

  12.  
  13. Install the inner rotor in the into the oil pump body. Measure the clearance between the inner and outer rotors. If the clearance between the rotors is 0.006 in. (0.150mm) or more the oil pump assembly must be replaced.

    Click image to see an enlarged view

    Fig. Install the inner rotor in the into the oil pump body. Use a feeler gauge (2) to measure the clearance between the inner (3) and outer (1) rotors. If the clearance between the rotors is 0.006 in. (0.150mm) or more the oil pump assembly must be replaced.

  14.  
  15. Place a straight edge across the body of the oil pump (between the bolt holes), if a feeler gauge of 0.0038 (0.095mm) or greater can be inserted between the straightedge and the rotors, the pump must be replaced.
    NOTE
    The oil pump on the 3.7L and 4.7L engines is released as an assembly. There are no DaimlerChrysler 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.



    Click image to see an enlarged view

    Fig. Place a straight edge (1) across the body of the oil pump (between the bolt holes), if a feeler gauge (2) of 0.0038 (0.095mm) or greater can be inserted between the straightedge and the rotors, the pump must be replaced

  16.  

The mating surface of the oil pump cover should be smooth. Replace pump assembly if cover is scratched or grooved.

  1. Lay a straightedge across the pump cover surface. If a 0.0015 in. (0.038mm) feeler gauge can be inserted between cover and straightedge, pump assembly should be replaced.
  2.  
  3. Measure the thickness and diameter of outer rotor. If outer rotor thickness measures 0.825 in. (20.9mm) or less, or if the diameter is 2.469 in. (62.7mm) or less, replace the outer rotor.
  4.  
  5. If inner rotor measures 0.825 in. (20.9mm) or less, replace inner rotor and shaft assembly.
  6.  
  7. Slide outer rotor into pump body. Press rotor to the side with your fingers and measure clearance between rotor and pump body. If the clearance is 0.014 in. (0.356mm) or more, replace oil pump assembly.
  8.  
  9. Install inner rotor and shaft into pump body. If clearance between inner and outer rotors is 0.008 in. (0.203mm) or more, replace shaft and both rotors.
  10.  
  11. Place a straightedge across the face of the pump, between bolt holes. If a feeler gauge of 0.004 in. (0.102mm) or more can be inserted between rotors and the straightedge, replace pump assembly.
  12.  
  13. Inspect the oil pressure relief valve plunger for scoring and free operation in its bore. Small marks may be removed with 400-grit wet or dry sandpaper.
  14.  
  15. The relief valve spring has a free length of approximately 1.95 in. (49.5mm). The spring should test between 19.5 and 20.5 pounds when compressed to 1 11 / 32 in. (34mm). Replace spring that fails to meet these specifications .
  16.  
  17. If oil pressure was low and pump is within specifications, inspect for worn engine bearings or other reasons for oil pressure loss.
  18.  

Removal & Installation



  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove or disconnect the following:

    Negative battery cables
     
    Accessory drive belt
     
    Cooling fan and shroud
     
    Radiator
     
    Oil fill tube and adapter
     
    Crankshaft pulley
     
    Front cover
     
    Oil pump

    Click image to see an enlarged view

    Fig. Oil pump torque sequence-5.9L diesel engine

     

  6.  

To install:


NOTE
When the pump is correctly installed, the flange on the pump does not touch the block; the back plate on the pump seats against the bottom of the bore.

  1. Install the oil pump. Tighten the bolts in sequence as follows:
    1. Step 1: 44 inch lbs. (5 Nm).
    2.  
    3. Step 2: 18 ft. lbs. (24 Nm).
    4.  

  2.  
  3. Install or connect the following:

    Front cover
     
    Crankshaft pulley
     
    Oil fill tube and adapter
     
    Radiator
     
    Cooling fan and shroud
     
    Accessory drive belt
     
    Negative battery cables
     

  4.  

3.7L Engine
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove or disconnect the following:

    Oil Pan
     
    Timing chain cover
     
    Timing chains and tensioners
     
    Oil pump
     

  4.  
  5. Installation is the reverse of removal. Torque the pump bolts, in sequence, to 21 ft. lbs. (28 Nm),
  6.  

3.9L, 5.2L, 5.9L Gasoline Engines
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Drain the engine oil.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable
     
    Oil pan
     
    Oil pump pick-up tube
     
    Oil pump

    Click image to see an enlarged view

    Fig. Exploded view of the oil pump assembly-3.9L, 5.2L and 5.9L engines

     

  6.  

To install:

  1. Install or connect the following:

    Oil pump. Tighten the bolts to 30 ft. lbs. (41 Nm).
     
    Oil pump pick-up tube
     
    Oil pan
     
    Negative battery cable
     

  2.  
  3. Fill the crankcase to the correct level.
  4.  
  5. Start the engine and check for leaks.
  6.  

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Drain the engine oil.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable
     
    Oil pan
     
    Oil pump from the rear main bearing cap
     

  6.  

To install:

  1. Install or connect the following:

    Oil pump. During installation, slowly rotate the pump body to make sure the driveshaft-to-pump rotor shaft engagement.
     
    Hold the oil pump base flush against the mating surface on No. 4 main bearing cap. Finger-tighten the pump attaching bolts. Tighten the attaching bolts to 30 ft. lbs. (41 Nm)
     
    Oil pan
     
    Negative battery cable
     

  2.  
  3. Fill the crankcase to the correct level.
  4.  
  5. Start the engine and check for leaks.
  6.  

  1. Remove the oil pan.
  2.  
  3. Remove the oil pump from the rear main bearing cap.
  4.  

To install:

  1. Install while slowly rotating the pump body to ensure drive shaft engagement.
  2.  
  3. Use a new gasket.
  4.  
  5. Hold the pump base flush against the mating surface on the main bearing cap and tighten the bolts to 30 ft. lbs. (41 Nm).
  6.  



Click image to see an enlarged view

Fig. Exploded view of oil pump-3.9L, 5.2L, 5.9L gasoline engines

4.7L Engine
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Drain the engine oil.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable
     
    Oil pan
     
    Oil pump pick-up tube
     
    Timing chains and tensioners
     
    Oil pump

    Click image to see an enlarged view

    Fig. Oil pump and chain tensioner torque sequence-3.7L and 4.7L engines

     

  6.  

To install:

  1. Install or connect the following:

    Oil pump. Tighten the bolts to 21 ft. lbs. (28 Nm).
     
    Timing chains and tensioners
     
    Oil pump pick-up tube
     
    Oil pan
     
    Negative battery cable
     

  2.  
  3. Fill the crankcase to the correct level.
  4.  
  5. Start the engine and check for leaks.
  6.  

  1. Remove the oil pan and pickup tube.
  2.  
  3. Remove the timing chain cover.
  4.  
  5. Remove the timing chains and tensioners.
  6.  
  7. Remove the four bolts, primary timing chain tensioner and oil pump.
  8.  

To install:

  1. Position the oil pump onto the crankshaft and install two mounting bolts.
  2.  
  3. Position the primary timing chain tensioner and install the two retaining bolts.
  4.  
  5. Tighten the pump and tensioner retaining bolts to 21 ft. lbs. (28 Nm) in the sequence shown.
  6.  
  7. Install the secondary timing chain tensioners, chains, cover, pickup tube and oil pan.
  8.  



Click image to see an enlarged view

Fig. Oil pump and primary timing chain tensioner tightening sequence-4.7L

5.7L Engines
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Drain the engine oil.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable
     
    Oil pan
     
    Oil pump pick-up tube
     
    Timing chains and tensioners
     
    Oil pump
     

  6.  

To install:

  1. Install or connect the following:

    Oil pump. Tighten the bolts to 21 ft. lbs. (28 Nm).
     
    Timing chains and tensioners
     
    Oil pump pick-up tube
     
    Oil pan
     
    Negative battery cable
     

  2.  
  3. Fill the crankcase to the correct level.
  4.  
  5. Start the engine and check for leaks.
  6.  

8.0L Engine
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable
     
    Accessory drive belt
     
    Cooling fan and shroud
     
    A/C compressor, if equipped
     
    Alternator
     
    Air injection pump
     
    Bracket assembly
     
    Water pump
     
    Crankshaft pulley
     
    Front oil pan bolts
     
    Front cover
     
    Oil pump pressure relief valve
     
    Oil pump cover
     
    Oil pump rotors
     

  6.  

To install:

  1. Install or connect the following:

    Oil pump rotors
     
    Oil pump cover. Tighten the bolts to 10 ft. lbs. (14 Nm).
     
    Oil pump pressure relief valve. Tighten the plug to 15 ft. lbs. (20 Nm).
     
    Front cover. Tighten the bolts to 35 ft. lbs. (47 Nm).
     
    Front oil pan bolts. Tighten the bolts to 12 ft. lbs. (16 Nm).
     
    Crankshaft pulley. Tighten the bolt to 135 ft. lbs. (183 Nm).
     
    Water pump
     
    Bracket assembly
     
    Air injection pump
     
    Alternator
     
    A/C compressor, if equipped
     
    Cooling fan and shroud
     
    Accessory drive belt
     
    Negative battery cable
     

  2.  
  3. Fill the cooling system.
  4.  
  5. Start the engine and check for leaks.
  6.  

  1. Remove the timing chain cover.
  2.  
  3. Remove the mounting screws and the oil pump cover.
  4.  

To install:

  1. Lubricate all of the pump internals with petroleum jelly or Lubriplate®.
  2.  
  3. Install the pump and tighten the pump cover to 10 ft. lbs. (14 Nm).
  4.  
  5. Make sure that the inner ring moves freely after the cover is installed.
  6.  
  7. Install the timing chain cover.
  8.  
  9. Squirt oil into the relief valve hole until the oil runs out.
  10.  
  11. Install the relief valve and spring.
  12.  
  13. Using a new pressure relief valve gasket, install the relief valve plug. Tighten it to 15 ft. lbs. (20 Nm).
  14.  
  15. Remember to fill the filter with oil before installation.
  16.  



Click image to see an enlarged view

Fig. Oil pump rotors-8.0L engine

Diesel Engines
  1. Disconnect the battery negative cables.
  2.  
  3. On 1997-99 models, remove the radiator.
  4.  
  5. Remove the oil fill tube, if necessary.
  6.  
  7. Remove the fan/drive assembly.
  8.  
  9. Remove the accessory drive belt.
  10.  
  11. Remove the fan support/hub assembly.
  12.  
  13. Remove the crankshaft damper.
  14.  
  15. Remove the gear cover-to-housing bolts and pry the cover away from the housing, taking care NOT to mar the gasket surface.
  16.  
  17. Remove the oil pump mounting bolts and remove the pump.
  18.  

To install:

  1. Fill the pump with clean engine oil.
  2.  
  3. Check that the idler gear pin is installed in the locating bore in the cylinder block.
  4.  
  5. Tighten the pump mounting bolts in two steps: first to 44 inch lbs. (5 Nm), and then to 18 ft. lbs. (24 Nm).
  6.  
  7. The back plate on the pump seats against the bottom of the bore in the cylinder block. When the pump is correctly installed, the flange on the pump will not touch the cylinder block.
  8.  
  9. Check the idler gear to pump drive gear backlash and the idler gear to crankshaft gear backlash. Replace the pump assembly if it exceeds 0.003-0.013 in. (0.080-0.330mm).
  10.  
  11. Tighten cover bolts to 18 ft. lbs. (24 Nm). Tighten vibration damper bolts to 92 ft. lbs. (125 Nm).
  12.  



Click image to see an enlarged view

Fig. Check backlash at each oil pump gear in turn-diesel

 
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