6
7
NOTCH
TM 9-4940-568-34
7-30
7-5. CRANKSHAFT AND BEARINGS REPLACEMENT (CONT).
NOTE
Crankshaft is a balanced, forged
steel unit with five main bearings.
Lower bearing shells are all the
same. All upper bearing shells
are also the same with the
exception of journal adjacent to
the rear one. The next to last
journal is fitted with a flanged
upper bearing shell. Flanges
control end thrust of the
crankshaft.
Upper bearings have three holes
in them. Middle hole receives
lubricating oil from main oil rifle.
One of the adjacent holes is
aligned with a drilling to
camshaft journal and serves as an
orifice for lubrication flow to the
journal. Other adjacent hole
supplies lubricating oil for piston
cooling. The hole does not align
perfectly with cooling nozzle.
The hole is off-set to keep it
away from highly loaded bearing
area. Make sure the tang on the
upper main bearing sets into the
notch.
(2)
Position upper main bearing (6) on engine
block bearing surface (7).
(3)
Repeat Step (2) for remaining upper
bearings.
