Isuzu Ascender 2003-05

Rear Main Seal

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Removal & Installation



4.2L Engines

Please note that the transmission assembly must be removed to perform this procedure.

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Transmission
     
    Flywheel
     
    Crankshaft rear main seal housing bolts. Install 2 bolts into the jackscrew holes to release the cover from the block
     


    Click image to see an enlarged view

    Fig. Install 2 bolts into the jackscrew holes (1) to push the cover off of the block-4.2L engine

    Crankshaft and rear main seal housing
     
    Rear main seal from the crankshaft snout
     

  4.  

To install:

  1. Install or connect the following:

    Rear main seal, using a suitable seal installation tool, then remove the tool
     
    Apply a 0.12 in. (3mm) bead of 12378521, or equivalent sealant to the rear mail seal housing
     
    Suitable cover alignment pins into the block
     

  2.  


NOTE
When you install a new seal, make sure to use the plastic installation sleeve supplies with the new seal. The sleeve should come off and be discarded after the seal is installed.

  1. Slide the crankshaft rear main seal housing over the alignment pins and crankshaft.
  2.  
  3. Install the crankshaft rear main seal housing bolts, except the 2 in place of the guide pins.
  4.  
  5. Remove the guide pins.
  6.  
  7. Install or connect the following:

    Remaining 2 crankshaft rear main seal housing bolts and tighten to 89 inch lbs. (10 Nm). Wipe off any excess sealant.
     
    Flywheel and secure with the mounting bolts. Tighten, in sequence, to 18 ft. lbs. (25 Nm), plus an additional 50 degrees.
     


    Click image to see an enlarged view

    Fig. Flywheel bolt tightening sequence-4.2L engine

    Transmission
     

  8.  

Please note that the transmission assembly must be removed to perform this procedure.

  1. Before servicing the vehicle, refer to the precautions section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Transmission
     
    Flywheel
     
    Crankshaft rear main seal housing bolts. Install 2 bolts into the jackscrew holes to release the cover from the block

    Click image to see an enlarged view

    Fig. Install 2 bolts into the jackscrew holes (1) to push the cover off of the block-4.2L engine

     
    Crankshaft and rear main seal housing
     
    Rear main seal from the crankshaft snout
     

  4.  

To install:

  1. Install or connect the following:
    NOTE
    When you install a new seal, make sure to use the plastic installation sleeve supplies with the new seal. The sleeve should come off and be discarded after the seal is installed.



    Rear main seal, using a suitable seal installation tool, then remove the tool
     
    Apply a 0.12 in. (3mm) bead of 12378521, or equivalent sealant to the rear mail seal housing
     
    Suitable cover alignment pins into the block
     

  2.  
  3. Slide the crankshaft rear main seal housing over the alignment pins and crankshaft.
  4.  
  5. Install the crankshaft rear main seal housing bolts, except the 2 in place of the guide pins.
  6.  
  7. Remove the guide pins.
  8.  
  9. Install or connect the following:

    Remaining 2 crankshaft rear main seal housing bolts and tighten to 89 inch lbs. (10 Nm). Wipe off any excess sealant.
     
    Flywheel and secure with the mounting bolts. Tighten, in sequence, to 18 ft. lbs. (25 Nm), plus an additional 50 degrees.

    Click image to see an enlarged view

    Fig. Flywheel bolt tightening sequence-4.2L engine

     
    Transmission
     

  10.  

5.3L Engine

Please note that the transmission assembly must be removed to perform this procedure.

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Transmission
     
    Flywheel
     
    Crankshaft rear main oil seal from the rear cover
     

  4.  


    Click image to see an enlarged view

    Fig. View of the rear main seal installation-5.3L engine


To install:


NOTE
The flywheel spacer (if applicable) must be removed prior to oil seal installation. Do not lubricate the oil seal Inside Diameter (ID) or crankshaft surface. Never reuse the rear main seal. Once it is removed, it must be replaced with a new seal.

  1. Lubricate the Outside Diameter (OD) of the rear main seal and the rear cover oil seal bore with clean engine oil. Do NOT let oil contact the seal surface or the crankshaft surface.
  2.  
  3. Install or connect the following:

    Crankshaft Rear Oil Seal Installer Tool No. J 41479 tapered cone and bolts onto the rear of the crankshaft. Tighten the bolts until just snug, being careful not to overtighten.
     
    Rear oil seal onto the tapered cone until the tool contacts the oil seal
     

  4.  
  5. Align the oil seal into the tool, Rotate the handle of the tool clockwise until the seal enters the rear cover and bottoms into the cover bore. Remove the tool.

    Flywheel and secure with the mounting bolts.
     

  6.  
  7. Tighten the flywheel mounting bolts, in sequence, as follows:
    1. 1st pass: 15 ft. lbs. (20 Nm)
    2.  
    3. 2nd pass: 37 ft. lbs. (50 Nm)
    4.  
    5. Final pass: 74 ft. lbs. (100 Nm)
    6.  


      Click image to see an enlarged view

      Fig. Flywheel bolt tightening sequence-5.3L engine

    7. Transmission
    8.  
    9. Negative battery cable
    10.  

  8.  
  9. Start the engine and verify no oil leaks.
  10.  

Please note that the transmission assembly must be removed to perform this procedure.

  1. Before servicing the vehicle, refer to the precautions section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Transmission
     
    Flywheel
     
    Crankshaft rear main oil seal from the rear cover

    Click image to see an enlarged view

    Fig. View of the rear main seal installation-5.3L engine

     

  4.  

To install:


NOTE
The flywheel spacer (if applicable) must be removed prior to oil seal installation. Do not lubricate the oil seal Inside Diameter (ID) or crankshaft surface. Never reuse the rear main seal. Once it is removed, it must be replaced with a new seal.

  1. Lubricate the Outside Diameter (OD) of the rear main seal and the rear cover oil seal bore with clean engine oil. Do NOT let oil contact the seal surface or the crankshaft surface.
  2.  
  3. Install or connect the following:

    Crankshaft Rear Oil Seal Installer Tool No. J 41479 tapered cone and bolts onto the rear of the crankshaft. Tighten the bolts until just snug, being careful not to overtighten.
     
    Rear oil seal onto the tapered cone until the tool contacts the oil seal
     

  4.  
  5. Align the oil seal into the tool, Rotate the handle of the tool clockwise until the seal enters the rear cover and bottoms into the cover bore. Remove the tool.

    Flywheel and secure with the mounting bolts.
     

  6.  
  7. Tighten the flywheel mounting bolts, in sequence, as follows:
    1. 1st pass: 15 ft. lbs. (20 Nm).
    2.  
    3. 2nd pass: 37 ft. lbs. (50 Nm).
    4.  
    5. Final pass: 74 ft. lbs. (100 Nm).

      Click image to see an enlarged view

      Fig. Flywheel bolt tightening sequence-5.3L engine



      Transmission
       
      Negative battery cable
       

    6.  

  8.  
  9. Start the engine and verify no oil leaks.
  10.  

 
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