SHAFT AS 4W0250 - Caterpillar

Removal Procedure
Table 1
Required Tools
Tool Part Number Part Description Qty
A 9U-6195 Valve Spring Compressor 1
B 9U-6198 Crankshaft Turning Tool 1 Start By:
Remove the rocker shaft assembly. Refer to Disassembly and Assembly, "Rocker Shaft and Pushrod - Remove".
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Note: The following procedure should be adopted in order to remove the valve springs when the cylinder head is still installed onto the cylinder block. Refer to Disassembly and Assembly Manual, "Inlet and Exhaust Valves - Remove and Install" for the correct procedure that should be used to remove the valve springs from a cylinder head that has been removed from the cylinder block.Note: Before you begin the removal of the valve springs, refer to Specifications, "Cylinder Head Valves" for appropriate information on the valve springs.
Ensure that the piston is at the top center position before the valve keepers are removed from the valve. Failure to ensure that the piston is at top dead center may allow the valve to drop into the cylinder block. Use the following procedure in order to find the top center position for the piston.
Do not turn the crankshaft while the valve springs are removed.
Illustration 1 g00937233
Personal injury can result from being struck by parts propelled by a released spring force.Make sure to wear all necessary protective equipment.Follow the recommended procedure and use all recommended tooling to release the spring force.
Install the Tooling (A).
Ensure that the valve spring is compressed squarely or damage to the valve stem may occur.
Compress the valve spring in order to open the valve. Do not compress the valve spring sufficiently so that the valve keepers (1) could be removed from the recess in the valve stem.
Turn the crankshaft until the piston touches the valve.
Continue to turn the crankshaft until the valve stem is at the highest point. The piston is now at the top center position. Release the pressure of the Tooling (A) when the piston is at the top center position.
Use Tooling (A) in order to compress valve spring (3). Remove valve keepers (1).
Carefully release the pressure on the Tooling (A). Remove the valve spring retainer (2) and the valve spring (3). Note: If you are replacing all of the valve springs, the procedure can be done on two cylinders at the same time. The procedure can be done on cylinder 1 and cylinder 4, and on cylinder 2 and cylinder 3.
Do not turn the crankshaft while the valve springs are removed.
Installation Procedure
Table 2
Required Tools
Tool Part Number Part Description Qty
A 9U-6195 Valve Spring Compressor 1
B 9U-6198 Crankshaft Turning Tool 1
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Illustration 2 g00937233
Improper assembly of parts that are spring loaded can cause bodily injury.To prevent possible injury, follow the established assembly procedure and wear protective equipment.
Place the new valve spring into position.
Install the valve spring retainer (2).
Ensure that the valve spring is compressed squarely or damage to the valve stem may