GM Celebrity/Century/Ciera/6000 1982-1996 Repair Guide

Rear Main Seal

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REMOVAL & INSTALLATION



2.2L and 2.5L Engines

See Figures 1 and 2

The rear main bearing seal is a one piece seal and can be removed without removal of the oil pan or the crankshaft.

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the engine oil from the vehicle.
  4.  
  5. Support the engine and remove the transaxle and flywheel.
  6.  
  7. Loosen the seal by inserting a flat bladed tool into the dust lip. Pry the seal out by moving the tool around the seal as required until the seal is removed.
  8.  



Click image to see an enlarged view

Fig. Fig. 1: Loosen the seal by inserting a flat-bladed tool into the dust lip. Pry the seal out by moving the tool around the seal as required until the seal is removed

Care must be taken not to damage the crankshaft seal surface with the prytool.

  1. Clean all of the block and crankshaft-to-seal mating areas.
  2.  
  3. Inspect the inside diameter bore for nicks or burrs.
  4.  
  5. Inspect the crankshaft for nicks or burrs on the seal contact surface. Repair or replace the crankshaft as needed.
  6.  



Click image to see an enlarged view

Fig. Fig. 2: Install the new seal using tool J-34686 or equivalent

To install:
  1. Lubricate the seal bore to the seal surface with engine oil.
  2.  
  3. Install the new seal using tool J-34686 or equivalent.
  4.  
  5. Slide the new seal over the mandrel until the dust lip bottoms squarely against the tool collar.
  6.  
  7. Next align the dowel pin of the tool with the dowel pin hole in the crankshaft, then attach the tool to the crankshaft. Tighten the screws to 45 inch lbs. (5 Nm).
  8.  
  9. Tighten the T-handle of the tool. Push the seal into the bore. Continue until the collar is flush against the cylinder block.
  10.  
  11. Loosen the T-handle completely, then remove the attaching screws and the tool.
  12.  
  13. Check to be sure the seal is seated properly into the bore.
  14.  
  15. Install the flywheel, then reverse to install the remaining components.
  16.  
  17. Add engine oil to the crankcase, as necessary.
  18.  
  19. Connect the negative battery cable.
  20.  
  21. Start the engine and check for leaks.
  22.  

2.8L Engine
2 PIECE SEAL

See Figures 3 and 4

  1. Drain the engine oil.
  2.  
  3. Remove the oil pan and pump.
  4.  
  5. Remove the rear main bearing cap.
  6.  
  7. Gently pack the upper seal into the groove approximately 1 / 4 - 3 / 4 in. (6-19mm) on each side.
  8.  



Click image to see an enlarged view

Fig. Fig. 3: Gently pack the upper seal into the groove

  1. Measure the amount the seal was driven in on one side, then add 1 / 16 in. (1.6mm). Cut this length from the old lower cap seal. Be sure to get a clean cut. Repeat for the other side.
  2.  
  3. Place the piece of cut seal into the groove and pack the seal into the block. Do this for each side.
  4.  



Click image to see an enlarged view

Fig. Fig. 4: Installing the new lower seal

GM makes a guide tool (J-29114-1) which bolts to the block via an oil pan bolt hole, and a packing tool (J-29114-2) which is machined to provide a built-in stop for the installation of the short cut pieces. Using the packing tool, work the short pieces of seal onto the guide tool, then pack them into the block with the packing tool.

  1. Install a new lower seal in the rear main cap.
  2.  
  3. Install a piece of Plastigage® or the equivalent on the bearing journal. Install the rear cap and tighten to 70 ft. lbs. (95 Nm). 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 sealing. Correct as required.
  4.  
  5. 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. (95 Nm), Install the pan and pump.
  6.  
  7. Add engine oil to the crankcase.
  8.  
  9. Start the engine and check for leaks.
  10.  

1-PIECE SEAL
  1. Drain the engine oil.
  2.  
  3. Remove the transaxle and the flexplate.
  4.  
  5. Using a small pry bar, pry the seal from the block.
  6.  


CAUTION
Be careful not to damage the crankshaft surface when removing the oil seal.

  1. Clean and inspect the seal mounting surface for nicks and burrs.
  2.  
  3. Coat the new seal with engine oil. Using tool J-34686, press the seal into the block, until it seats.
  4.  
  5. To complete the installation, reverse the removal procedures.
  6.  
  7. Add engine oil to the crankcase.
  8.  
  9. Start the engine and check for leaks.
  10.  

3.0L Engine
LOWER OIL SEAL
  1. Remove the crankshaft.
  2.  
  3. Remove the old seal and place a new seal in the groove with both ends projecting the surface of the cap.
  4.  
  5. Force the seal into the groove rubbing down with a hammer handle or smooth stick until the seal projects above the groove not more than 1 / 16 in. (1.6mm). Cut ends off flush with surface of cap, using sharp knife or razor blade.
  6.  
  7. The engine must be operated at slow speed when first started after a new braided seal is installed. Neoprene composition seals are placed in grooves in the sides of bearing cap to seal against leakage in the joints between cap and crankcase. The neoprene composition swells in the presence of oil and heat. The seals are undersize when newly installed and may even leak for a short time until the seals have had time to swell and seal the opening.
  8.  
  9. The neoprene seals are slightly longer than the grooves in the bearing cap. The seals must not be cut to length. Before installation of seals, soak for 1 to 2 minutes in light oil or kerosene. After installation of bearing cap in crankcase, install seal in bearing cap.
  10.  
  11. To help eliminate oil leakage at the joint where the cap meets the crankcase, apply sealer, to the rear main bearing cap split line. When applying sealer, use only a thin coat as an over abundance will not allow the cap to seat properly.
  12.  

UPPER OIL SEAL
  1. Drain the engine oil.
  2.  
  3. Remove oil pan.
  4.  
  5. Insert packing tool (J-21526-2 or equivalent) against one end of the seal in the cylinder block. Drive the old seal gently into the groove until it is packed tight. This varies from 1 / 4 in. (6mm) to 3 / 4 in. (19mm) depending on the amount of pack required.
  6.  
  7. Repeat on the other end of the seal in the cylinder block.
  8.  
  9. Measure the amount the seal was driven up on one side and add 1 / 16 in. (1.6mm). Using a single edge razor blade, cut that length from the old seal removed from the rear main bearing cap. Repeat the procedure for the other side. Use the rear main bearing cap as a holding fixture when cutting the seal.
  10.  
  11. Install guide tool (J-21526-1 or equivalent) onto cylinder block.
  12.  
  13. Using packing tool, work the short pieces cut previously into the guide tool and then pack into cylinder block. The guide tool and packing tool have been machined to provide a built-in stop. Use this procedure for both sides. It may help to use oil on the short pieces of the rope seal when packing into the cylinder block.
  14.  
  15. Remove the guide tool.
  16.  
  17. Install a new fabric seal in the rear main bearing cap. Install cap and tighten to specifications.
  18.  
  19. Install oil pan.
  20.  
  21. Add engine oil to the crankcase, as necessary.
  22.  
  23. Start the engine and check for leaks.
  24.  

3.1L and 3.3L Engines
  1. Disconnect the negative battery cable.
  2.  
  3. Drain the engine oil.
  4.  
  5. Remove the transaxle.
  6.  
  7. Remove the flywheel mounting bolts and remove the flywheel and spacer.
  8.  
  9. Using a small pry bar, pry the seal from the block.
  10.  


CAUTION
Be careful not to damage the crankshaft surface when removing the oil seal.

  1. Clean the seal mounting surface.
  2.  

To install:
  1. Coat the inside and outside of the new rear main oil seal with engine oil.
  2.  
  3. Install the new seal on tool J-34686 (or equivalent) until the seal bottom is squarely against the collar of the tool.
  4.  
  5. Align the dowel pin of the tool with the dowel pin hole in the crankshaft. Tighten the attaching screws to 45 inch lbs. (5 Nm).
  6.  
  7. Turn the handle of the tool until the collar is tight against the case. This will ensure the seal is fully seated.
  8.  
  9. Back the tool off and remove the attaching screws.
  10.  
  11. Install the flywheel and spacer and tighten the flywheel mounting bolts.
  12.  
  13. Install the transaxle assembly.
  14.  
  15. Connect the negative battery cable.
  16.  
  17. Add engine oil to the crankcase.
  18.  
  19. Start the engine and check for leaks.
  20.  

3.8L Engine
  1. Disconnect the negative battery cable.
  2.  
  3. Raise and support the vehicle safely.
  4.  
  5. Drain the engine oil and remove the oil pan.
  6.  
  7. Remove the rear main bearing cap. Remove the oil seal from the bearing cap.
  8.  

To install:
  1. Insert a packing tool (J-21526-2 or equivalent) against one end of the seal in the cylinder block. Pack the old seal in until it is tight. Pack the other end of seal in the same manner.
  2.  
  3. Measure the amount the seal was driven up into the block on one side and add approximately 3 / 32 in. (2mm). With a single edge razor blade, cut this amount off of the old lower seal. The bearing cap can be used as a holding fixture.
  4.  
  5. Install the packing guide tool J-21526-1 or equivalent, onto the cylinder block.
  6.  
  7. Using the packing tool, work the short pieces of the seal into the guide tool and pack into the cylinder block until the tool hits the built in stop. Repeat this step on the other side. A small amount of oil on the pieces of seal may be helpful when packing into the cylinder block.
  8.  
  9. Remove the guide tool.
  10.  
  11. Install a new rope seal in the bearing cap and install the cap. Tighten the retaining bolts to specification.
  12.  
  13. Install the oil pan.
  14.  
  15. Fill the crankcase with oil.
  16.  
  17. Connect the negative battery cable.
  18.  
  19. Start the vehicle and check for leaks.
  20.  

4.3L Diesel Engine
LOWER OIL SEAL
  1. Remove the rear main bearing cap.
  2.  
  3. Remove the old seal and place a new seal in the groove with both ends projecting the surface of the cap.
  4.  
  5. Force the seal into the groove rubbing down with a hammer handle or smooth stick until the seal projects above the groove not more than 1 / 16 in. (1.6mm). Cut ends off flush with surface of cap, using sharp knife or razor blade.
  6.  
  7. The engine must be operated at slow speed when first started after a new braided seal is installed. Neoprene composition seals are placed in grooves in the sides of bearing cap to seal against leakage in the joints between cap and crankcase. The neoprene composition swells in the presence of oil and heat. The seals are undersize when newly installed and may even leak for a short time until the seals have had time to swell and seal the opening.
  8.  
  9. The neoprene seals are slightly longer than the grooves in the bearing cap. The seals must not be cut to length. Before installation of seals, soak for 1 to 2 minutes in light oil or kerosene. After installation of bearing cap in crankcase, install seal in bearing cap.
  10.  
  11. To help eliminate oil leakage at the joint where the cap meets the crankcase, apply sealer to the rear main bearing cap split line. When applying sealer, use only a thin coat as an over abundance will not allow the cap to seat properly.
  12.  

UPPER OIL SEAL
  1. Drain the engine oil.
  2.  
  3. Remove oil pan.
  4.  
  5. Insert packing tool (J-21526-2 or equivalent) against one end of the seal in the cylinder block. Drive the old seal gently into the groove until it is packed tight. This varies from 1 / 4 in. (6mm) to 3 / 4 in. (19mm) depending on the amount of pack required.
  6.  
  7. Repeat on the other end of the seal in the cylinder block.
  8.  
  9. Measure the amount the seal was driven up on one side and add 1 / 16 in. (1.6mm). Using a single edge razor blade, cut that length from the old seal removed from the rear main bearing cap. Repeat the procedure for the other side. Use the rear main bearing cap as a holding fixture when cutting the seal.
  10.  
  11. Install Guide Tool (J-21526-1) onto cylinder block.
  12.  
  13. Using packing tool, work the short pieces cut previously into the guide tool and then pack into cylinder block. The guide tool and packing tool have been machined to provide a built-in stop. Use this procedure for both sides. It may help to use oil on the short pieces of the rope seal when packing into the cylinder block.
  14.  
  15. Remove the guide tool.
  16.  
  17. Install a new fabric seal in the rear main bearing cap. Install cap and tighten to specification.
  18.  
  19. Install oil pan.
  20.  
  21. Add engine oil to the crankcase.
  22.  
  23. Start the engine and check for leaks.
  24.  

 
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