GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 42841-A Rear Oil Seal Remover

    Important: Although originally equipped with a lip-style crankshaft rear oil seal, engines built from March 1, 1996 and thru 1999 should now use the cassette-style crankshaft rear oil seal.

    Important: If the engine is in the vehicle, the crankshaft rear oil seal can be removed/installed after the transmission/transaxle and engine flywheel are removed.

    Important: Crankshaft rear oil seal removal requires adequate space for removal. Mount the engine on a suitable engine stand which will properly space the engine in order to use the J 42841-A in order to remove the crankshaft rear oil seal. If necessary, remove the crankshaft rear oil seal with the engine properly supported on the floor or on a bench.

    Important: Beginning with the model year 2006 the flywheel/flexplate crankshaft bolt hole thread was changed from 8 x 1.25 mm to 11 x 1.5 mm. The J 42841-A will service the cassette seals installed on engines from March 1, 1996 and later. If the older J 42841 is to be used on a 2006 or later engine the update kit, J 42841-10, must be used to convert the J 42841 to a J 42841-A .


    Object Number: 548455  Size: SH
  1. Install the J 42841-A plate onto the crankshaft. The hub on the crankshaft will fit into the recess on the inboard side of the J 42841-A plate.

  2. Object Number: 689376  Size: SH

    Important: Northstar engines 2005 and older have an 8 x 1.25 mm flywheel/flexplate crankshaft bolt hole thread. Northstar engines 2006 and later have an 11 x 1.5 mm flywheel/flexplate crankshaft bolt hole thread.

  3. Use the proper bolts from the J 42841-A to retain the plate in place. Use the bolts (1) 8 mm or the bolts (2) 11 mm.

  4. Object Number: 548457  Size: SH
  5. Using a drill motor, variable speed preferred, with a socket adapter, install eight 25 mm (1.0 in) self-drilling screws into the seal using the guide holes in the removal tool. When drilling, ensure the drill motor speed is reduced when the screw begins threading into the seal.

  6. Object Number: 548458  Size: SH
  7. With all eight removal screws installed, remove the J 42841-A retaining bolts.

  8. Object Number: 548460  Size: SH
  9. Install the center forcing screw.

  10. Object Number: 548461  Size: SH
  11. Tighten the center screw on the J 42841-A in order to pull the seal assembly off the end of the crankshaft.

  12. Object Number: 1770170  Size: SH
  13. After removing the crankshaft rear oil seal inspect the engine block bore (1) and the crankshaft flange (2) for the damage. Repair or replace any damaged components.