BOLT 7X0389 - Caterpillar

All 3500 Series EnginesValve failures are possible after replacement of the valve lifters on 3500 Series Engines.
The 7N4782 Springs are used on the 2W3256 Lifter Assemblies to prevent rotation of the lifter assemblies in the cylinder head. If during assembly, the lifter assemblies are pushed all the way into the cylinder head or if the cylinder head is put down on the lifter assemblies, the springs can be pushed too deeply into the head. As a result, the springs will not permit the lifter assemblies to contact the camshaft.
Because the springs are very strong, the serviceman can adjust the valve lash and not know that the lifter assemblies are not against the camshaft. When the engine is started, the springs will move downward. As a result, the valve lash adjustment will change, and valve failures are possible.
To prevent these problems, first, the serviceman must not put the head down on the lifter assemblies.
Second, after the installation of the head and rocker arm assemblies, the serviceman must push down on each rocker arm assembly and lightly hit the adjustment screw with a plastic hammer. This will force the components against each other.
After the above step is complete, the Service Manual procedure must then be used to adjust the valve lash.
Location of components.