20-63. MAIN BEARING AND CRANKSHAFT REPAIR (CONT).
Fuel is very flammable and can explode easily. To avoid serious injury or death, keep fuel away
from open fire and keep fire extinguisher within easy reach when working with fuel. Do not
work on fuel system when engine is hot. Fuel can be ignited by hot engine.
Clean crankshaft (1) and bearing caps (2)
with diesel fuel and cleaning cloth.
Flush oil passages (3) in crankshaft and
clean using a stiff wire brush.
Visually inspect crankshaft (1) for signs of
overheating. Replace crankshaft if journals
have turned blue from heat.
Inspect crankshaft connecting rod
journals (4) and main bearing journals (5)
for deep scratches. Replace crankshaft if
Inspect connecting rod journals (4) and
main bearing journals (5) for signs of cracks
at connecting rod journal oil holes (6) or at
joining points (7) of connecting rod journal
and main bearing journals. Replace
crankshaft if damaged.
Inspect crankshaft keyways (8) for cracks or
gouges. Replace crankshaft (1) if damaged.
Inspect rear oil seal contact surface (9) for
deep scratching. If scratches cannot be
smoothed out with crocus cloth, replace
Inspect crankshaft thrust surfaces (10) for
grooving. Replace crankshaft (1) if deep
grooves have been scratched into thrust
Timing gear was removed from
crankshaft during crankshaft
Inspect timing gear (11) for chipped teeth.
Replace if damaged.