Camshaft Replacement. Buick Roadmaster 1996

For 1990-2009 cars

#### Tools Required

J 7872 Magnetic Base Indicator Set

### Removal Procedure

1. Recover the R134a refrigerant. Refer to Handling Refrigerant-134a in Heating and Air Conditioning.
2. Remove the intake manifold. Refer to Intake Manifold Replacement .
3. Remove the valve rocker arms and the valve rocker pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .
4. Remove the oil pump driveshaft bolt.
5. Remove the oil pump driveshaft.
6. Remove the water pump. Refer to Water Pump Replacement
7. Remove the engine front cover. Refer to Engine Front Cover Replacement .
8. Remove the camshaft sprocket. Refer to Timing Chain, Sprockets, and WP Driveshaft Replace .
9. Remove the valve lifters. Refer to Valve Lifter Replacement .
10. Remove the radiator. Refer to Radiator Replacement in Cooling and Radiator.
11. Remove the air conditioner condenser. Refer to Air Conditioning Condenser in Heating and Air Conditioning.
12. Remove the camshaft retainer bolts.
13. Remove the camshaft retainer.

Important: All of the camshaft journals are the same diameter. Use care when removing the camshaft in order to avoid damage to the bearings.

14. Remove the camshaft as follows:

14.1. | Install three 5/16-18 x 4.0 inch bolts in the camshaft bolt holes.

14.2. | Carefully rotate and pull the camshaft out of the bearings.

### Inspection Procedure

1. Inspect the camshaft journals with a micrometer. Replace the camshaft if the journals are more than 0.025 mm (0.0010 inch) out-of-round.
2. Inspect the camshaft runout. Complete the following steps:

2.1. | Mount the camshaft in V-blocks.

2.2. | Use the J 7872 in order to check the intermediate camshaft journal.

2.3. | Replace the camshaft if runout exceeds 0.038 mm (0.0015 inch).

3. Inspect the camshaft lobe lift with a micrometer.
4. Measure the camshaft lobe high point.
5. Measure the camshaft lobe low point.
6. Subtract the camshaft lobe low point from the high point. Compare the results to the specifications listed. Refer to Engine Mechanical Specifications .
7. Inspect the camshaft bearings for scratches, pits, or loose fit in their bores. Replace the camshaft bearings, if necessary.

### Installation Procedure

1. When installing a new camshaft, coat the camshaft lobes with prelube, GM P/N 1052365 or the equivalent.
2. When installing a new camshaft, replace all of the valve lifters in order to ensure the durability of the camshaft lobes and the lifter rollers.
3. Lubricate all of the camshaft journals with the engine oil.
4. Install the camshaft.
5. Install the camshaft retainer.

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.

6. Install the camshaft retainer bolts.

Tighten
Tighten the camshaft retainer bolts to 12 N·m (106 lb in).

7. Install the air conditioning condenser. Refer to Air Conditioning Condenser in Heating and Air Conditioning.
8. Install the radiator. Refer to Radiator Replacement in Cooling and Radiator.
9. Install the valve lifters. Refer to Valve Lifter Replacement .
10. Install the camshaft sprocket. Refer to Timing Chain, Sprockets, and WP Driveshaft Replace .
11. Install the engine front cover. Refer to Engine Front Cover Replacement .
12. Install the water pump. Refer to Water Pump Replacement .
13. Install the oil pump driveshaft.
14. Install the oil pump driveshaft bolt.

Tighten
Tighten the bolt to 18 N·m (13 lb ft).

15. Install the valve rocker arms and the pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .
16. Install the intake manifold. Refer to Intake Manifold Replacement .
17. Charge the air conditioning system with R134a refrigerant. Refer to Refrigerant Recovery and Reycling, Adding Oil, Evacuating and Recharging in Heating and Air Conditioning.