Oil Pump (Unit Repair) Assembly - L81: Installation

IMPORTANT:  Do not cover and/or restrict gasket openings with excess sealant.

1. Coat pump side (crosshatched area shown in illustration) of new oil pump gasket with a thin, even coating of Permatex Anaerobic Sealant or equivalent.
2. Install oil pump gasket.
   Fig 1: Installing Oil Pump Gasket

   Courtesy of GENERAL MOTORS CORP.
3. Install oil pump and align with the guide pins. Ensure that mating surface is clean and free of oil or grease.
   Fig 2: Installing Oil Pump And Align With The Guide Pins

   Courtesy of GENERAL MOTORS CORP.
4. Apply Permatex(R) Threadlocker Blue(R) sealant or equivalent to the oil pump bolts and install bolts.

   Torque: 

   Oil Pump Bolts - L81: 20 N.m (15 ft-lbs) 

   Fig 3: Applying Sealant And Installing Bolts

   Courtesy of GENERAL MOTORS CORP.
5. Install oil pump collar.
6. Install front main oil seal. Coat lip of front main oil seal with a small amount of clean engine oil to aid in installation.
7. Use Camshaft Front Main Seal Installer J35268A to install front main oil seal into place. Ensure front main oil seal is fully and evenly seated.
8. Install crankshaft drive gear.
9. Install new crankshaft drive gear bolt.
   Fig 4: Installing Crankshaft Drive Gear And New Crankshaft Drive Gear Bolt

   Courtesy of GENERAL MOTORS CORP.
10. Install crank hub holding tool J42065 to hold drive gear and tighten bolt using crank hub torx socket J42098

    Torque: 

    Crankshaft Drive Gear Bolt - L81: 250 N.m (184 ft-lbs) + 45° + 15° 

    Fig 5: Installing Crank Hub Holding Tool

    Courtesy of GENERAL MOTORS CORP.
    NOTE: The oil pump bolts must be re-tightened AFTER the generator mounting bolt has been tightened to specifications to allow for uniform compression of the oil pump gasket.
11. Temporally mount the generator and install the generator lower mounting bolt (3).

    Torque: 

    Generator Mounting Bolts - L81: 40 N.m (30 ft-lbs) 

12. Re-tighten the oil pump bolts in sequence.

    Torque: 

    Oil Pump Bolts - L81: 20 N.m (15 in-lbs) 

13. Remove the generator bolt and the generator.
    Fig 6: Tightening Oil Pump Bolts In Sequence

    Courtesy of GENERAL MOTORS CORP.