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DESCRIPTION & OPERATION
Crankshaft
The crankshaft is fully counterbalanced and has
induction hardened journals. There are seven
main bearings with thrust washers located at the
center main bearing (position No. 4) to absorb
fore and aft end thrust. Crankshaft extension at
the forward end carries the main drive gear,
vibration damper and accessory drive pulleys.
The main drive gear has a shrink fit and the
vibration damper hub has a press fit. The main
drive gear is keyed to the crankshaft for proper
assembly and engine timing. The flywheel is
mounted to a flange at the rear of the crankshaft.
Two seals, one at the front and one at the rear,
prevent engine lubricating oil from leaking around
the ends of the crankshaft.
Bearing caps are furnished with the crankcase
and support the crankshaft in true alignment.
Webs integral to the crankcase provide the upper
half of the main bearing supports. Removable
caps provide the lower support and are held in
position with capscrews. The bearing caps are
not interchangeable and each has a number
stamped on it which signifies its correct location
and alignment in the crankcase. The caps are
numbered 1 through 7, with the No. 1 main
bearing cap at the front of the engine. The
bearing inserts are precision-designed, and are
positioned between the crankshaft and
crankcase, and between the crankshaft and the
bearing caps. Thrust flanges to support the thrust
washers are located at the center main bearing
(No. 4).
Block Heater for Front (Water
Pump) Location
The engine accepts a straight element unit in the
rear location. Front installations require a curved-
element heater (Figure 42). This curved element
is located inside the lower part of the water pump
housing, which has been revised to
accommodate it. With factory installations, CH/CL
models use the rear location, while RD, MR and
other Macungie-built models use the front
location.
42
Figure 42 — Straight and Curved Block Heaters
5_106_00.bk Page 40 Friday, August 4, 2000 11:17 AM
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