Usage:
Preparing To Set Valve Lash
- 1. Stop the engine.
- 2. Remove the flywheel housing timing cover.
REMOVING TIMING COVER
- 3. Wipe the base of the valve cover(s) to keep dirt from getting into the valve mechanism.
- 4. Remove the valve cover(s).
- 5. Bar the flywheel in the direction of normal rotation. Align the "TC-1" timing mark with the flywheel housing timing pointer.
BARRING FLYWHEEL
- 6. Observe the rockers for cylinder No. 1. Determine if the piston is on COMPRESSION or EXHAUST STROKE.
COMPRESSION STROKE: Both inlet and exhaust valve rockers, or roller arms, can be easily moved with finger pressure.
EXHAUST STROKE: Only inlet valve rockers, or roller arms, can be moved freely with finger pressure.
- 7. Refer to the tables below, and set only those valves specified in the appropriate table:
- 8. Bar the flywheel one revolution in the direction of normal rotation and align the flywheel "TC-1" timing mark.
- 9. Set the remaining valves as specified in the remaining table.
Setting Valve Lash: D330, D333 Engines
- 1. Loosen the locknut on the adjusting screw.
- 2. Hold the locknut and turn the adjusting screw to obtain the proper lash.
- 3. Hold the adjusting screw and tighten the locknut.
- 4. Recheck the lash.
Setting Valve Lash: D334, D336 Engines
- 1. Turn the adjusting screw counterclockwise 2 clicks or more to provide clearance between the rocker assembly and the valve stem.
- 2. Turn the adjusting screw clockwise to obtain zero lash; the exact position where rocking movement of the rocker, or lateral movement of the adjusting screw button can no longer be detected.
| NOTICE |
|---|
The adjusting screw button can be rotated by finger pressure when it is in contact with the valve stem. |
Turning the adjusting screw clockwise beyond this point will lift the valve off its seat, and final lash setting will be incorrect.
- 3. Turn the adjusting screw counterclockwise for the specified number of clicks shown in the Lubrication and Maintenance Chart.
Valve Rotators
Checking Rotation
After checking all valve clearances, and before installing the valve covers:
- 1. Start the engine.
- 2. Move the governor control to low idle position.
- 3. Watch the serrations on each valve retainer. Each valve retainer should turn slightly each time the valve closes.
If a valve retainer fails to rotate, repairs are required. Call your Caterpillar dealer.
If all valves rotate, proceed as follows:
- 4. Stop the engine.
- 5. Inspect and install valve cover gaskets. Install new gaskets if necessary.
- 6. Install the valve cover(s).
- 7. Install the flywheel housing timing cover.