CAB AS 4960803 - Caterpillar

Check the Timing of the Crankshaft and Camshaft
The timing of the crankshaft and camshaft must be checked, and the valve bridge must be adjusted before the valve lash is adjusted. Correctly time the camshafts with the crankshaft before adjusting the fuel timing.
If the camshaft is rotated with the timing pin installed, the timing pin will break. This can result in further damage. Make sure to remove the timing pin before the camshaft is rotated.
DO NOT use the starting motor to rotate the crankshaft. The lubrication oil can drain out from between the crankshaft and the engine bearings if the engine has not been operated for a period of time. Damage can result if the crankshaft is rotated on dry bearing surfaces.To prevent damage to the crankshaft bearings, DO NOT crank the engine before prelube, especially after this maintenance procedure.
The prelube pump should not be operated continuously for extended periods of time. If, during repairs, the prelube pump has run continuously for a period of three hours or more, it will be necessary to remove any oil that may have collected in the cylinders and/or above the valves.
Prelube of the engine is required before the crankshaft is rotated for normal maintenance. Activate the prelube pump for rotating the engine crankshaft.
Do not use an impact wrench to operate the barring device. The use of an impact wrench will cause gear tooth failure.
The barring device provides a means for slowly turning the flywheel in order to service the engine. The barring device can also be used to prevent rotation of the crankshaft.Fuel Injector Timing (Fuel Timing)
Correctly time the camshafts with the crankshaft before adjusting the fuel timing. The fuel timing dimension is stamped on the engine Information Plate.Fuel Injector Clamp
The clamp must be used to draw the injector into the bore. Do not tap on the top of the injector. Be sure to protect the spray tip from dirt and damage.Valve Bridge
Do NOT attempt to adjust the valves if the crankshaft and camshaft are not synchronized. Disregard for this can result in engine damage such as bent valves.
Check the valve bridge and adjust the valve bridge, if necessary. Perform the procedure for both valve bridges for each cylinder.After the valve bridge is satisfactory, check the valve lash.Engine Valve Lash
If the valve lash is within the tolerance, an adjustment of the valve lash is NOT necessary.The crankshaft and camshaft timing must be checked, and valve bridge adjustment must be performed before making a valve lash adjustment.Perform the valve lash setting when the engine is cold. After the engine has been shut down and the valve covers are removed, the engine is considered cold.Before performing maintenance, prevent the entry of foreign matter into the top of the cylinder head and the valve mechanism. Thoroughly clean the area around the valve mechanism covers.