COLLET 8R3945 - Caterpillar

Installation Procedure
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Illustration 1 g00539829
Loosen adjusting screws (3). This will prevent a bent valve or a bent pushrod during the installation of the rocker shaft assembly. Install pushrods (2) and ensure that the pushrods are seated in the valve lifters.
Install rocker shaft assembly (1) in position on the cylinder head.
Ensure that the dowels on each end of the rocker shaft assembly are in alignment with the holes in the cylinder head.
Illustration 2 g00544706
Numerical sequence for tightening the bolts for the rocker shaft assemblyNote: Replace the O-ring seal when the bolt toward the rear of the engine is installed in the rocker shaft support.
Apply 6V-4876 Lubricant on the threads of six bolts (4) except for the bolt that passes through the rear rocker shaft support (bolt (6) in Illustration 2). Install six bolts (4) in the rocker shaft assembly.
Refer to Illustration 2. Tighten six bolts (4) for the rocker shaft, as follows:
Tighten all of the bolts in the numerical sequence to a torque of 155 N m (115 lb ft).
Tighten all of the bolts in the numerical sequence to a torque of 250 17 N m (185 13 lb ft).
Tighten all of the bolts again in the numerical sequence to a final torque of 250 17 N m (185 13 lb ft).
The assembled length of the springs at both ends of the rocker shaft must be 1.50 0.25 mm (.059 .010 inch). Remove the washers or install the washers behind the springs in order to change the assembled length of the springs.
Adjust the inlet valve lash to 0.38 0.08 mm (.015 .003 inch) and adjust the exhaust valve lash to 0.64 0.08 mm (.025 .003 inch). Refer to Testing and Adjusting, "Air Inlet and Exhaust System" for more information on setting the valve lash. Tighten the locknuts for the adjusting screws (3) to a torque of 29 7 N m (21 5 lb ft). Refer to Specifications, "Valve Rocker Arms and Lifters".End By: Install the valve mechanism cover. Refer to Disassembly and Assembly, "Valve Mechanism Cover - Remove and Install".