Isuzu Cars and Trucks 1981-1991

Rear Main Bearing Oil Seal

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REMOVAL AND INSTALLATION
One Piece Seal

NOTE
All engines, except the 4ZC1, 4ZD1 and 4ZE1 have one piece rear crankshaft oil seals. The oil pan does not have to be remove to access the seal.

  1. Disconnect the negative battery cable. Raise and safely support the vehicle.
  2.  
  3. Drain the engine oil and remove the oil pan.
  4.  


CAUTION
The EPA warns that prolonged contact with used engine oil may cause a number of skin disorders, including cancer! You should make every effort to minimize your exposure to used engine oil. Protective gloves should be worn when changing the oil. Wash your hands and any other exposed skin areas as soon as possible after exposure to used engine oil. Soap and water, or waterless hand cleaner should be used.

  1. If equipped with an automatic transmission, remove the transmission. If equipped with a manual transmission, remove the transmission and clutch assembly.
  2.  
  3. Remove the starter without disconnecting the wires and secure it aside.
  4.  
  5. Remove the flywheel-to-crankshaft bolts and the flywheel.
  6.  
  7. Carefully, remove the oil seal, using a small pry bar; work the tool around the diameter of the seal until the seal begins to lift out. Use care not to damage the seat and area around the seal.
  8.  
  9. Fill the space between the seal lips with grease and lubricate the seal lips with clean engine oil. Install the new oil seal.
  10.  
  11. Install the flywheel, transmission and starter motor.
  12.  
  13. Connect the battery cable, start the engine and check for leaks.
  14.  



Click image to see an enlarged view

Fig. One piece crankshaft rear oil seal

Two Piece Seal

Both halves of the rear main oil seal can be replaced without removing the crankshaft. Always replace the upper and lower seal together. The lip should face the front of the engine. Be very careful that you do not break the sealing bead in the channel on the outside portion of the seal while installing it. An installation tool can be fabricated to protect the seal bead.

  1. Remove the oil pan and rear main bearing cap.
  2.  
  3. Remove the oil seal from the bearing cap by prying it out.
  4.  
  5. Remove the upper half of the seal with a small punch. Drive it around far enough to be gripped with pliers. Be very careful not to damage the crankshaft sealing surface.
  6.  

To install:

  1. Clean the crankshaft and bearing cap.
  2.  
  3. Coat the lips and bead of the seal with light engine oil, keeping oil from the ends of the seal.
  4.  
  5. Position the a suitable tool between the crankshaft and seal seat.
  6.  
  7. Position the seal between the crankshaft and tip of the tool so that the seal bead contacts the tip of the tool. The oil seal lip should face forward.
  8.  
  9. Roll the seal around the crankshaft using the tool to protect the seal bead from the sharp corners of the crankcase.
  10.  
  11. The installation tool should be left installed until the seal is properly positioned with both ends flush with the block.
  12.  
  13. Remove the tool.
  14.  
  15. Install the other half of the seal in the bearing cap using the tool in the same manner as before. Light thumb pressure should install the seal.
  16.  
  17. Install the bearing cap with sealant applied to the mating areas of the cap and block. Keep sealant from the ends of the seal.
  18.  
  19. Torque the rear main bearing cap to specifications.
  20.  
  21. Install the oil pan and refill the engine with oil. Start the engine and check for leaks.
  22.  



Click image to see an enlarged view

Fig. Two piece crankshaft rear oil seal. Apply sealer to the areas indicated by arrows

 
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