Tools Required

J 37228 Seal Cutter

1. Drain the engine coolant and the engine block. Refer to Cooling System Draining and Filling in Engine Cooling.
2. Remove the starter. Refer to Starter Motor Replacement in Engine Electrical.
3. Remove the transmission. Refer to Transmission Replacement in Automatic Transmission - Allison or Transmission Replacement in Manual Transmission - ZF S6-650.
4. Remove the flywheel. Refer to Engine Flywheel Replacement - Automatic Transmission or Engine Flywheel Replacement - Manual Transmission .



5. Remove the turbocharger oil return pipe nuts from the top of the flywheel housing.



6. Remove the crankshaft rear oil seal. Refer to Crankshaft Rear Oil Seal Replacement .
7. Remove the oil filter.

Important: The engine flywheel housing has dowels that protrude into the upper oil pan and the engine block. The upper oil pan requires removal for proper installation of the engine flywheel housing.

8. Remove the upper oil pan. Refer to Upper Oil Pan Replacement .



9. Remove the engine rear cover bolts, denoted by a black circle.



10. Remove the nuts retaining the coolant duct to the engine flywheel housing.
11. Remove the seal (1) and the gasket (2) from the coolant duct.
12. Clean the sealing surfaces of both the seal (1) and the gasket (2).
13. Remove the bolts retaining the coolant duct to the oil filter adapter and oil cooler assembly.
14. Separate the flywheel housing from the cylinder block using the J 37228 .
15. Remove the engine rear cover.



16. Remove the O-rings from the engine flywheel housing.
17. Clean the sealing surfaces on the engine flywheel housing and the engine block.
18. Clean the engine flywheel housing in clean solvent and air dry.
19. Clean the engine flywheel housing O-ring sealing area.
20. Inspect the engine flywheel housing for cracks.
21. Inspect the crankshaft rear oil seal bore for damage.
22. Replace the engine flywheel housing if any damage is found.

1. Install the 2 O-rings in the engine flywheel housing.



2. Apply a 2 mm (1/8 in) wide bead of sealant (3) GM P/N 12378521 or equivalent to the engine rear cover sealing surfaces.



3. Install a new gasket to the oil filter adapter for the coolant duct
4. Install the new gasket (2) and the new seal (1) on the coolant duct.
5. Install the coolant duct to the flywheel housing.
6. Loosely install the coolant duct to the flywheel housing nuts.
7. Install the engine flywheel housing to the engine block.

Notice: Refer to Fastener Notice in the Preface section.





Important: The upper oil pan bolts are denoted by a black triangle. These bolts are torqued at 50 N·m (37 lb ft).

8. Install the engine flywheel housing bolts, denoted by a black circle.

Tighten
Tighten the flywheel housing bolts to 95 N·m (70 lb ft).




9. Install the coolant duct to oil filter adapter assembly bolts.

Tighten

1. Tighten the coolant duct to oil filter adapter bolts to 21 N·m (15 lb ft).
2. Tighten the coolant duct to engine flywheel housing nuts to 21 N·m (15 lb ft).



10. Install a new gasket to the turbocharger oil return pipe.
11. Install the turbocharger oil return pipe to engine flywheel housing nuts.

Tighten
Tighten the turbocharger oil return pipe nuts to 21 N·m (15 lb ft).

12. Install the upper oil pan. Refer to Upper Oil Pan Replacement .
13. Install the crankshaft rear oil seal. Refer to Crankshaft Rear Oil Seal Replacement .
14. Install the flywheel. Refer to Engine Flywheel Replacement - Automatic Transmission or Engine Flywheel Replacement - Manual Transmission .
15. Install the transmission. Refer to Transmission Replacement in Automatic Transmission - Allison or Transmission Replacement in Manual Transmission - ZF S6-650.



16. Install the starter. Refer to Starter Motor Replacement in Engine Electrical.
17. Install a new oil filter.

Tighten
Tighten the oil filter after contact 1 to 1¼ turns.

18. Lower the vehicle.
19. Fill the engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.