Rocker Arm: Removal
WARNING: This page is about a different variant/trim than selected.
- Remove the valve cover(s) for the cylinders being serviced. For additional information, refer to VALVE COVER LH or VALVE COVER RH .
- Locate the dowel hole in the vibration damper.
- The hole is located between two of the four bolts that attach the damper to the front of the crankshaft.
- Rotate the crankshaft until the dowel hole is at the 12 o'clock position.
- The No. 1 piston should be on the compression stroke. Wiggle the rocker on the No. 1 cylinder to verify both intake and exhaust rocker arms are able to move freely. If the intake and exhaust rocker arms do not move freely, rotate the crankshaft one complete revolution. You are now positioned to service the rocker arms for cylinders 1, 2, 7 and 8.
- If required, skip Step 5 and complete the rest of the procedure, for rocker arms on cylinders 1, 2, 7 and 8.
- If you are not servicing cylinders 1, 2, 7 and 8 or if service to those cylinders has been completed, rotate the crankshaft one complete revolution to service the rocker arms for cylinders 3, 4, 5 and 6.
- Complete the rest of this procedure for rocker arms on cylinders 3, 4, 5 and 6.
- Remove the fuel injectors for the cylinders that are being serviced. For additional information, refer to FUEL INJECTORS .
- Insert the injector hold-down clamp into the special tool base.
- Install the assembly in between the bridges as if you are installing an injector.
- Install the rubber hose in the oil drain holes for the cylinder on which the rocker arms are being serviced.
- Verify that the oil drain holes are blocked.
- Install the special tool plate on top of the bridges with the small point of the plate in between the exhaust rocker and bridge. Install the special tool bolt and compress the valve springs until the plate contacts the top of the tool base.
- Disengage the rocker arm from the push rod. Then rotate the rocker arm out while compressing down on the rocker arm retaining clip.
- Remove and discard the rocker arm retaining clip.
- Repeat the step for the other rocker arm.
- Remove the push rod.
- Inspect each push rod for wear and deposits which may restrict the flow of oil into the rocker arm assembly, install new push rods as necessary.
- Check the push rods for flatness by rolling them on a flat surface. If not within specification, install new push rods as necessary.
- With the rocker arms removed, remove the special tool bolt and the special tool plate to gain access to the valve bridges.
- Remove and discard the valve bridges.
NOTE:
For vehicles with a single generator, use a long arm box wrench to rotate the engine. Use an inspection mirror to verify that the dowel hole is in the 12 o'clock position.
NOTE:
If servicing all rocker arms, or any of the rocker arms for cylinders 1, 2, 7 and 8, the remainder of this procedure must be performed before rotating the crankshaft to prepare the engine to service cylinders 3, 4, 5 and 6.
NOTE:
All service for cylinders 1, 2, 7 and 8 must be completed before rotating the crankshaft to prepare the engine to service cylinders 3, 4, 5 and 6.
NOTE:
Make sure the notch in the base is aligned in the hold-down clamp.
CAUTION:
While centering the base between the two bridges, snug the hold-down bolt only. Do not tighten it or engine damage can occur.
NOTE:
Use a piece of 457.2 mm (18 in) x 6.35 mm (0.25 in) vacuum hose to block the oil drain holes.
NOTE:
Apply clean engine oil to the hose to aid in installing.
CAUTION:
Only use hand tools to compress the valve springs. Do not use power tools or engine damage can occur.
NOTE:
If the rocker arm is severely worn, insert a small pry bar between the exhaust rocker arm and bridge to gain clearance by compressing the valves slightly.
NOTE:
When removing the rocker arm, be careful not to drop the ball from the fulcrum plate or rocker arm socket.
CAUTION:
To prevent engine damage, keep the push rods in the order in which they were removed. Install the push rods back in their original positions.