Bearing retainer lock
Lock pin spring
Hub & back plate
341. Crane Engine Cylinder Head Cleaning,
344. Crane Engine Valve Assemblies Cleaning,
Inspection, and Repair
Inspection and Repair
a. Cleaning. Clean all parts with an approved
cleaning solvent and dry thoroughly.
Clean all parts with an approved cleaning
b. Inspection and Repair. Check flatness of the
cylinder head gasket contact surfaces with a straight edge
Clean carbon from valves, valve stems,
and feeler gauge in three positions lengthwise and five
and cylinder block and from around valve
crosswise. The maximum permissible is .004 inches low
seats and ports.
in the center lengthwise, gradually decreasing towards the
ends, or .003 inches crosswise or in localized spots.
b. Inspection and Repair.
Replace a defective cylinder head.
Inspect the valves for burned seats and
342. Crane Engine Cylinder Head Installation
pitted or bent stems. Stem diameter should
be 0.4335 to 0.4345 inch. Replace valves
a. Install cylinder head and tighten nuts in sequence
with bent or worn stems or badly burned
b. Install thermostat and housing assembly (para.
Inspect the inside of each valve guide for
proper clearance. Intake should be 0.4360
to 0.4370 inch. Exhaust should be 0.4390
to 0.4400 inch. Replace defective or worn
Inspect the exhaust valve seat inserts.
Replace any that are loose, cracked or
g. Fill the cooling system.
343. Crane Engine Valve Assemblies Removal and
Inspect the valve springs for proper tension.
They should have a load of 93 to 99 pounds
when compressed to 1 3/8 inches. Replace
springs when they do not come within
Remove valve covers and gaskets (para.
Inspect the tappets for worn threads,
scores, cracks, and wear or pitting on the
face. Replace defective tappets. Tappet
Remove the valve assemblies from the
hole diameter should be between 1.125 and
b. Disassembly. Disassemble the valve assemblies
Inspect tappet adjusting screws and nut
in the numerical sequence as illustrated in figure 193.
locks for worn or damaged threads.
Replace if defective.