SEAL-O-RING 3110827 - Caterpillar

Valve Lash
Preparing To Check Adjustment
1. Stop the engine.2. Remove the flywheel housing timing cover(s).
REMOVING TIMING COVER(S)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. Move the compression release lever to the START position, if engine is so equipped.
COMPRESSION RELEASE LEVER6. Bar the flywheel counterclockwise. Align the "TC 1" timing mark on the flywheel with the timing pointer on the flywheel housing.7. 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 can be moved freely.EXHAUST STROKE: Only inlet valve rocker(s) can be moved freely.Numbering Of Cylinders And Valve Location
D342 ENGINES
D343 ENGINES ONLY
D353 ENGINES8. With NO. 1 CYLINDER ON COMPRESSION STROKE, check the lash of the following valves; adjust if necessary. 9. With NO. 1 CYLINDER ON EXHAUST STROKE, check the lash of the following valves; adjust if necessary. 10. Bar the flywheel one revolution in the direction of normal rotation and align the flywheel "TC 1" timing mark with the timing pointer.11. Set the remaining valves as specified in the remaining chart.Adjusting Valve Lash
D342 and D353 Engines
1. Loosen the locknut on the adjusting screw.
LOOSENING LOCKNUT2. Hold the locknut and turn the adjusting screw to obtain the proper lash.
ADJUSTING VALVE LASH3. Hold the adjusting screw and tighten the locknut.4. Recheck the lash.D343 Engines
1. Insert a cross point (Phillips) screwdriver in the hole in the side of the cam follower and engage the cam follower adjuster gear.2. Turn the screwdriver clockwise to increase lash or counterclockwise to decrease lash.3. Recheck the lash.
ADJUSTING VALVE LASH (D343 Engine only)
CHECKING VALVE LASHValve 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. D342 and D353 Engines: Watch the serrations on each valve retainer. Each valve retainer should turn slightly each time the valve closes.D343 Engines: Watch the cam followers. Each cam follower should slowly rotate while the engine is running. However, cam follower rotation does not necessarily indicate valve rotation.If it is suspected a valve is not rotating, contact your Caterpillar dealer. Repairs must be made to prevent burning the valve.If all valves rotate, proceed as follows:4. Stop the engine.5. Inspect and install valve cover gaskets. Install new gaskets if necessary.
CHECK VALVES FOR ROTATION (D342 shown)6. Install the valve covers.7. Install the flywheel housing timing cover(s).