TM 5-3895-346-14
ENGINE OVERHAUL
CRANKSHAFT
CRANKSHAFT
The crankshaft (Fig. 1) is a one-piece steel forging, heat-treated to ensure strength and durability. All main
and connecting rod bearing journal surfaces, oil seal surfaces and fillets on 4-53 vehicle engine crankshafts are
induction hardened.
Complete static and dynamic balance of the crankshaft has been achieved by counterweights incorporated in
the crankshaft.
The crankshaft end play is controlled by thrust washers located at the rear main bearing cap of the engine. Full
pressure lubrication to all connecting rod and main bearings is provided by drilled passages within the
crankshaft and cylinder block.
On certain 4-53 engines, a crankshaft with splines at the front end is used. These engines use a splined
crankshaft pulley and pulley mounting components.
Remove Crankshaft
When removal of the crankshaft becomes necessary, first remove the transmission, then proceed as follows:
1. Clean the exterior of the engine.
2. Drain the cooling system.
3. Drain the engine crankcase.
4. Remove all engine to base attaching bolts. Then, with a chain hoist and sling attached to the lifter
brackets at each end of the engine, remove the engine from its base.
5. Remove all of the accessories and assemblies with their attaching parts as necessary to permit the engine
to be mounted on an overhaul stand.
6. Mount the engine on an overhaul stand and fasten it securely to the mounting plate.
Figure 1. Crankshaft Details and Relative Location of Parts (Three-Cylinder
In-Line Engine Crankshaft Shown)
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