TM 5-3895-346-14
ENGINE OVERHAUL
VALVE OPERATING MECHANISM
CAUTION
It is important to use the correct bolts as prescribed in the parts books. The
hardened bolt is necessary to obtain the proper torque and to withstand the stress
imposed on it during engine operation.
Install Rocker Arms and Shaft
Note that the injector rocker arm (center arm of the group) is slightly different from the exhaust valve rocker
arms; the boss for the shaft on the left and right-hand valve rocker arms is longer on one side. The extended
boss of each valve rocker arm must face toward the injector rocker arm.
1. Thread each rocker arm on its push rod until the end of the push rod is flush with or above the inner side
of the clevis yoke. This will provide sufficient initial clearance between the exhaust valve and the piston when
the crankshaft is turned during the valve clearance adjustment procedure.
2. If removed, install the cylinder head on the engine (refer to Cylinder Head).
3. If removed, install the fuel injectors.
4. Apply clean engine oil to the rocker arm shaft and slide the shaft through the rocker arms. Then place a
bracket over each end of the shaft, with the finished face of the bracket next to the rocker arm.
5. Insert the rocker arm bracket bolts through the brackets and the shaft. Tighten the bolts to the specified
torque (refer to Specifications). Check to make sure there is some clearance between the rocker arms.
CAUTION
On four-valve cylinder heads, there is a possibility of damaging the exhaust valves
if the valve bridge is not resting on the ends of the valves when tightening the
rocker arm shaft bracket bolts (Fig. 11). Therefore, note the position of the valve
bridges before, during, and after tightening the bolts.
6. Align the fuel pipes and connect them to the injectors and the fuel connectors. Tighten the fuel pipe nuts
to 12-15 lb ft (16-20 Nm) torque using socket J 8932-01.
CAUTION
Do not bend the fuel pipes and do not exceed the specified torque. Excessive
tightening will twist or fracture the flared ends of the fuel pipes and result in leaks.
Lubricating oil diluted by fuel oil can cause serious damage to the engine bearings.
7. Fill the cooling system.
8. Adjust the exhaust valve clearance (Exhaust Valve Clearance) and time the injectors (Fuel Injector
Timing).
9. If necessary, perform an engine tuneup.
89
