40140 Mercury NUT, (M10)

Table 1
Required Tools
Tool Part Number Part Description Qty
A 9U-6195 Valve Spring Compressor 1
268-1969 Adapter 1
276-1221 Head 1 Start By:
Remove the cylinder head. Refer to Disassembly and Assembly, "Cylinder Head - Remove" for the correct procedure.
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Clean the bottom mating surface of the cylinder head. Check the depth of the valves below the face of the cylinder head before the valve springs are removed. Refer to Specifications, "Cylinder Head Valves" for the correct dimensions.
Place a temporary identification mark on the heads of the valves to identify the correct position.Note: Inlet valves have a recess in the center of the head.
Use a suitable lifting device to position the cylinder head with the valve springs upward. The weight of the cylinder head is approximately 65 kg (143 lb).Note: Ensure that the cylinder head is kept on a clean, soft surface to prevent damage to the machined face.
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.
Illustration 1 g01978994
Install Tooling (A) into position on the cylinder head to compress appropriate valve spring (3).
Ensure that the valve spring is compressed squarely or damage to the valve stem may occur.
Apply sufficient pressure to Tooling (A) to remove valve keepers (1).Note: Do not compress the spring so that valve spring retainer (2) touches valve stem seal (4).
Slowly release the pressure on Tooling (A).
Illustration 2 g01978995
Place a temporary identification mark on valve spring (3) to identify the correct position.
Remove valve spring retainer (2). Remove valve spring (3).
Repeat Step 4 through Step 8 for the remaining valves.
Remove Tooling (A).
Remove valve stem seals (4).
Use a suitable lifting device to turn over the cylinder head.
Place a temporary identification mark on valves (5). Remove valves (5) from the cylinder head.Installation Procedure
Table 2
Required Tools
Tool Part Number Part Description Qty
A 9U-6195 Valve Spring Compressor 1
268-1969 Adapter 1
276-1221 Head 1
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Note: The valves have a hard surface finish. Grinding compound must not be used on the valves. Grinding compound will damage the hard surface finish of the valves.
Clean all components of the cylinder head assembly. Ensure that all ports, all coolant passages, and, all lubrication passages in the cylinder head are free from debris. Follow Step 1a through Step 1e to inspect the components of the cylinder head assembly. Replace any components that are worn or damaged.
Inspect the cylinder head for wear and for damage. Refer to System Operation, Testing and Adjusting, "Cylinder Head Inspect" for the correct procedure.
Inspect the valve seats for wear and for damage. Refer to Specifications, "Cylinder Head Valves" for more information.
Inspect the valve guides for wear and for damage. Refer to Specifications, "Cylinder Head Valves" and System Operation, Testing and Adjusting, "Valve Guide - Inspect" for more information.Removal and installation of the valve guide and valve seat must be carried out by personnel with the correct training. Also special machinery is required. For more information, refer to your authorized Cat dealer.
Inspect the valves for wear and for damage. Refer to Specifications, "Cylinder Head Valves" for more information.
Inspect the valve springs for damage and for the correct length. Refer to Specifications, "Cylinder Head Valves" for more information.
Illustration 3 g01978995
Lubricate the stems of valves (5) with clean engine oil. Install valves (5) in the appropriate positions in the cylinder head. Check the depth of the valves below the face of the cylinder head. Refer to System Operation, Testing and Adjusting, "Valve Depth - Inspect" for more information.
Use a suitable lifting device to turn over the cylinder head. The weight of the cylinder head is approximately 65 kg (143 lb).Note: Ensure that all of the valves remain in place.
Install new valve stem seals (4) onto each of the valve guides.Note: The outer face of the valve guides must be clean and dry before installing valve stem seals (4).
Inst