Mazda B-Series 1998-06

Rear Main Seal

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Removal & Installation



If the crankshaft rear oil seal replacement is the only operation being performed, it can be done in the vehicle as detailed in the following procedure. If the oil seal is being replaced in conjunction with a rear main bearing replacement, the engine must be removed from the vehicle and installed on a work stand.

  1. Remove the transmission from the vehicle, following the procedures in Section 7.
  2.  
  3. On a manual shift transmission, remove the pressure plate and cover assembly and the clutch disc following the procedure in Section 7.
  4.  
  5. Remove the flywheel and engine rear cover plate.
  6.  
  7. Use an awl to punch two holes in the crankshaft rear oil seal. Punch the holes on opposite sides of the crankshaft and just above the bearing cap to cylinder block split line. Install a sheet metal screw in each hole. Use two large screwdrivers or small pry bars and pry against both screws at the same time to remove the crankshaft rear oil seal. It may be necessary to place small blocks of wood against the cylinder block to provide a fulcrum point for the pry bars. Use caution throughout this procedure to avoid scratching or otherwise damaging the crankshaft oil seal surface.
  8.  

To install:

  1. Clean the oil seal recess in the cylinder block and main bearing cap.
  2.  
  3. Clean, inspect and polish the rear oil seal rubbing surface on the crankshaft. Coat a new oil seal and the crankshaft with a light film of engine oil. Start the seal in the recess with the seal lip facing forward and install it with the following special seal driver tool, or equivalent:
  4.  



Click image to see an enlarged view

Fig. Installation of rear main seal and installed height



2.3L engine-49-UN01-070
 
2.5L engine-49-UN01-170
 
3.0L engine-49-UN01-064
 
4.0L engine-49-UN01-009
 

  1. Keep the tool straight with the centerline of the crankshaft and install the seal until the tool contacts the cylinder block surface. Remove the tool and inspect the seal to be sure it was not damaged during installation.
  2.  
  3. Inspect the installed height of the seal. The height should measure 0.02 inch (0.5mm) for the 2.3L, 2.5L and 3.0L engines, and 0.421-0.425 inch (10.7-10.9mm) for the 4.0L engine.
  4.  
  5. Install the engine rear cover plate.
  6.  
  7. Install the flywheel.
  8.  
  9. On a manual shift transmission, install the clutch disc and the pressure plate assembly following the procedure in Section 7.
  10.  
  11. Install the transmission, following the procedure in Section 7.
  12.  

2.3L Engine


Flywheel or flexplate
 
Bolts and the crankshaft rear oil seal
 

To install



Rear oil seal on the Crankshaft Rear Main Oil Seal Installer
 
Crankshaft Rear Main Oil Seal Installer and the crankshaft rear oil seal on the crankshaft

Click image to see an enlarged view

Fig. rear main seal torque sequence-2.3L

 

  1. Tighten the bolts in the sequence shown to 10 Nm (89 inch lbs.)
  2.  
  3. Remove the Crankshaft Rear Main Oil Seal Installer.
  4.  
  5. Install the flywheel or flexplate. .
  6.  

2.5L Engine
  1. Remove the flywheel or flexplate
    NOTE
    Clean the crankshaft rear oil seal and cylinder block prior to removing the rear oil seal.

  2.  
  3. Screw in the Jet Plug Remover.
  4.  
  5. Remove the seal.
  6.  

To install


NOTE
Apply 5W30 motor oil to seal and seal edge.

  1. Install crankshaft rear oil seal on Rear Main Seal Replacer.
  2.  
  3. Install the Rear Main Seal Replacer and the crankshaft rear oil seal on the crankshaft.
  4.  
  5. Alternate bolt tightening to crankshaft rear oil seal.
  6.  
  7. Install the flywheel or flexplate.
  8.  

3.0L & 4.0L OHV Engines
  1. Remove the flexplate or flywheel.
    WARNING
    Use care to avoid scratching or damaging the oil seal surface or leakage may occur.

  2.  
  3. Using a sharp awl, punch one hole into the crankshaft rear oil seal metal surface between the seal lip and the cylinder block.
  4.  
  5. Screw the threaded end of the special tool into the oil seal. Use the special tool to remove the crankshaft rear oil seal.
  6.  

To install:

  1. Lubricate the outer lips and the inner seal on the crankshaft rear oil seal with clean engine oil.
  2.  
  3. Using the special tool, install the crankshaft rear oil seal. Alternate bolt tightening to correctly seat the crankshaft rear oil seal.
  4.  
  5. Install the flexplate or flywheel.
  6.  

3.0L Engines
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove the flexplate or flywheel.
    WARNING
    Use care to avoid scratching or damaging the oil seal surface or leakage may occur.

  4.  
  5. Using a sharp awl, punch one hole into the crankshaft rear oil seal metal surface between the seal lip and the cylinder block.
  6.  
  7. Screw the threaded end of the special tool into the oil seal. Use the special tool to remove the crankshaft rear oil seal.

    Click image to see an enlarged view

    Fig. Rear main seal removal-3.0L engine

  8.  

To install:

Click image to see an enlarged view

Fig. Rear main seal installation-3.0L engine

  1. Lubricate the outer lips and the inner seal on the crankshaft rear oil seal with clean engine oil.
  2.  
  3. Using the special tool, install the crankshaft rear oil seal. Alternate bolt tightening to correctly seat the crankshaft rear oil seal.
  4.  
  5. Install the flexplate or flywheel.
  6.  

4.0L Engine
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove the flexplate or flywheel.
    WARNING
    Avoid scratching or damaging the oil crankshaft seal running surface during removal of the crankshaft rear oil seal.

  4.  
  5. Using the special tool, remove the crankshaft rear oil seal.

    Click image to see an enlarged view

    Fig. Rear main seal removal-4.0L engine

  6.  

To install:

Click image to see an enlarged view

Fig. Front part of rear main seal installation tool-4.0L engine



Click image to see an enlarged view

Fig. Rear main seal installation-4.0L engine


NOTE
Be sure the crankshaft rear sealing surface is clean and free of any rust or corrosion. To clean the crankshaft rear sealing surface, use extra-fine emery cloth or extra-fine 0000 steel wool with metal surface cleaner.

  1. Lubricate the crankshaft rear oil seal with clean engine oil and install on the special tool.
  2.  
  3. Using the special tool, install the crankshaft rear oil seal.
  4.  
  5. Install the flexplate or flywheel.
  6.  

SOHC Engine
  1. Remove the flexplate or flywheel.
    WARNING
    Avoid scratching or damaging the oil crankshaft seal running surface during removal of the crankshaft rear oil seal.

  2.  
  3. Using the special tool, remove the crankshaft rear oil seal.
  4.  

To install:


NOTE
Be sure the crankshaft rear sealing surface is clean and free of any rust or corrosion. To clean the crankshaft rear sealing surface, use extra-fine emery cloth or extra-fine 0000 steel wool with metal surface cleaner.

  1. Lubricate the crankshaft rear oil seal with clean engine oil and install on the special tool.
  2.  
  3. Using the special tool, install the crankshaft rear oil seal.
  4.  
  5. Install the flexplate or flywheel.
  6.  

 
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