Removal Procedure
- Remove the valve rocker arm cover. Refer to:
Important: Mark, sort, and organize all the components for assembly.
- Remove the valve rocker arms.
- Remove the valve rocker arm supports.
- Remove the valve pushrods.
Important: Parts that are to be reused must be marked, sorted, and organized for
assembly.
- Mark, sort, and organize the components for assembly.
Caution: Wear safety glasses in order to avoid eye damage.
- Clean the components with cleaning
solvent.
- Dry the components with compressed air.
- Inspect the valve rocker arm components for the following:
| • | Valve rocker arm valve pushrod socket contact surface (1) |
| • | The contact surface must be smooth with no scoring or excessive wear. |
| • | Valve rocker arm roller pivot for binding or damage (2) |
| • | Valve rocker arm valve stem contact surface (3) |
| • | The contact surface should be smooth with no scoring or excessive wear. |
| • | Valve rocker arm bolt threads for damage (4) |
- Inspect the valve pushrods for the following:
| • | Restriction of the oil passage (1) |
| • | Wear or scoring of the end contact surfaces (2) |
| • | The end contact surfaces must be smooth with no scoring or excessive
wear. |
| • | Roll the valve pushrod on a flat surface to determine if the valve pushrod
is bent. |
- Inspect the valve rocker support for
excessive wear or damage.
Installation Procedure
Important: Be sure to keep parts in order. Parts must be reinstalled into the original
location and position.
- Install the valve pushrods.
Important: Be sure that the arrow on the valve rocker arm support is in the up
position.
- Install the valve rocker arm supports.
- Apply prelube GM P/N 12345501
or equivalent to the following valve rocker arm contact surfaces:
| • | Valve pushrod socket (1) |
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.
- Install the valve rocker arm assemblies
as follows:
| 4.1. | Finger start the bolt at location (1) |
| 4.2. | Finger start the bolt at location (2) |
| 4.3. | Finger start the bolt at location (3) |
| 4.4. | Finger start the remaining valve rocker arm bolts |
- Rotate the crankshaft balancer to position
the crankshaft balancer alignment mark (1) 57-63 degrees clockwise
or counterclockwise from the engine front cover alignment tab (2).
Important: Once the valve rocker arm assemblies are installed and properly torqued,
no additional valve lash adjustment is required.
- Tighten the valve rocker arm bolts.
Tighten
Tighten valve rocker arm bolts to 30 N·m (22 lb ft).
- Install the valve rocker arm cover. Refer to:
