1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
2. If equipped, remove the oil pan skid plate bolts and plate.



3. Remove the oil pan drain plug and drain the oil into a suitable container.



4. Remove the oil filter.



5. If equipped with 2 wheel drive (2WD), remove the crossbar bolts and bar.



6. If equipped with 4 wheel drive (4WD), remove the crossbar bolts and bar.
7. If equipped with 4WD, remove the front differential carrier. Refer to Differential Carrier Assembly Replacement in Front Drive Axle.



8. Remove the battery cable bracket bolts.
9. Remove the starter. Refer to Starter Motor Replacement in Engine Electrical.



10. Remove the transmission cover.



11. Remove the transmission oil cooler liner bracket bolt, if equipped.



12. Disconnect the low oil level sensor electrical connector (7).



13. Remove the access plugs for the oil pan rear nuts.



14. Remove the transmission bolts (manual transmission shown).




Important: The low oil level sensor is not reusable.

15. Remove and discard the engine oil level sensor.



16. Remove the oil pan bolts and nuts.



17. Remove the oil pan.



18. Remove and discard the oil pan gasket.
19. Clean and inspect the oil pan, if necessary. Refer to Oil Pan Cleaning and Inspection in Engine Mechanical - 4.3L Unit Repair.

Notice: Any time the transmission and the engine oil pan are off of the engine at the same time, install the transmission before the oil pan. This is to allow for the proper oil pan alignment. Failure to achieve the correct oil pan alignment can result in transmission failure.

1. Apply a 5 mm (0.197 in) wide and 25 mm (1.0 in) long bead of adhesive GM U.S. P/N 12346141, Canada P/N 10953433, or equivalent to both the right and left sides of the front cover to engine block junction at the oil pan sealing surfaces.



2. Apply a 5 mm (0.197 in) wide and 25 mm (1.0 in) long bead of adhesive GM U.S. P/N 12346141, Canada P/N 10953433, or equivalent to both the right and left sides of the rear oil seal housing to engine block junction at the oil pan sealing surfaces.




Important: Always install a NEW oil pan gasket.

The oil pan gasket and oil pan must be installed and the fasteners tightened while the adhesive is still wet to the touch.
3. Install the NEW oil pan gasket into the groove in the oil pan.




Important: The oil pan alignment must always be flush or forward no more than 0.3 mm (0.011 in) from the rear face of the engine block.

4. Install the oil pan onto the engine block.

Press the oil pan gasket into the grooves of the engine front cover and crankshaft rear oil seal housing.

5. Slide the oil pan back against a suitable straight edge.



6. Install the oil pan bolts and nuts until snug.
7. Measure the pan-to-transmission housing clearance using a feeler gage and a straight edge.

Use a feeler gage to check the clearance between the oil pan-to-transmission housing measurement points. If the clearance exceeds 0.3 mm (0.011 in) at any of the 3 oil pan-to-transmission housing measurement points (1), then repeat the step until the oil pan-to-transmission housing clearance is within the specification. The oil pan must always be forward of the rear face of the engine block.





Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

8. Tighten the oil pan bolts and nuts in the sequence shown.

Tighten
Tighten the oil pan bolts to 25 N·m (18 lb ft).

9. Measure the clearance between the 3 oil pan-to-transmission housing measurement points in order to ensure proper alignment.



10. Install a NEW oil pan drain plug O-ring seal onto the oil pan drain plug.
11. Install the oil pan drain plug into the oil pan.

Tighten
Tighten the oil pan drain plug to 25 N·m (18 lb ft).





Important: The low oil level sensor is not reusable. Use a NEW low oil sensor.

12. Install a NEW engine oil level sensor.

Tighten
Tighten the engine oil level sensor to 13 N·m (115 lb in).




13. Install the transmission cover.

Tighten
Tighten the transmission cover bolts to 12 N·m (106 lb in).




14. Install the transmission bolts (manual transmission shown).

Tighten
Tighten the transmission bolts to 50 N·m (37 lb ft).




15. Install the access plugs for the oil pan rear nuts,



16. Install the transmission oil cooler line bracket bolt, if equipped.

Tighten
Tighten the transmission oil cooler line bracket bolt to 9 N·m (80 lb in).




17. Install the starter. Refer to Starter Motor Replacement in Engine Electrical.
18. Connect the low oil level sensor electrical connector (7).



19. Install the battery cable bracket bolts.

Tighten
Tighten the battery cable bracket bolts to 12 N·m (106 lb in).




20. If equipped with 2WD, Install the crossbar and bolts.

Tighten
Tighten the crossbar bolts to 100 N·m (74 lb ft).




21. If equipped with 4WD, install the front differential carrier, if equipped. Refer to Differential Carrier Assembly Replacement in Front Drive Axle.
22. If equipped with 4WD, install the crossbar and bolts.

Tighten
Tighten the crossbar bolts to 100 N·m (74 lb ft).




23. If equipped, install the oil pan skid plate and bolts.

Tighten
Tighten the oil pan skid plate bolts to 20 N·m (15 lb ft).




24. Lubricate the oil filter gasket with clean engine oil.
25. Install the oil filter to the engine.

Tighten
Tighten the oil filter to 30 N·m (22 lb ft).

26. Lower the vehicle.
27. Fill the engine with the proper capacity and quality of engine oil. Refer to Approximate Fluid Capacities in Maintenance and Lubrication.