Chevrolet Citation/Omega/Phoenix/Skylark 1980-1985 Repair Guide

Rear Main Oil Seal



Four Cylinder

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Fig. Fig. 1 The 4-cylinder engine has a one piece ring type rear main seal

The rear main oil seal is a one piece unit, and is removed or installed without removal of the oil pan or crankshaft.

  1. Remove the transaxle, the flywheel or torque converter bellhousing, and the flywheel or flexplate.
  3. Remove the rear main oil seal with a prytool. Be extremely careful not to scratch the crankshaft.

To install:

  1. Oil the lips of the new seal with clean engine oil. Install the new seal by hand onto the rear crankshaft flange. The helical lip of the seal should face the engine. Make sure that the seal is firmly and evenly installed.
  3. Replace the flywheel or flexplate, bellhousing and transaxle.

Six Cylinder

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Fig. Fig. 2 Pack the old upper seal into its grove 1/4 in. on each side

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Fig. Fig. 3 Use the bearing cap to hold the old lower seal while you cut it

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Fig. Fig. 4 Location of the sealer application for 6-cylinder engines

  1. Remove the oil pan and pump.
  3. Remove the rear main bearing cap.
  5. Gently pack the upper seal into the groove approximately 1 / 4 inch on each side.
  7. Measure the amount the seal was driven in on one side and add 1 / 16 in. Cut this length from the old lower cap seal. Be sure to get a sharp cut. Repeat for the other side.
  9. Place the piece of cut seal into the groove and pack the seal into the block. Do this for each side.
  11. Install a new lower seal in the rear main cap.
  13. Install a piece of Plastigage or the equivalent on the bearing journal. Install the rear cap and tighten to 75 ft. lbs. Remove the cap and check the gauge for bearing clearance. If out of specification, the ends of the seal may be frayed or not flush, preventing the cap from proper seating. Correct as required.
  15. Clean the journal, and apply a thin film of sealer to the mating surfaces of the cap and block. Do not allow any sealer to get onto the journal or bearing. Install the bearing cap and tighten to 70 ft. lbs. Install the pan and pump.