GMC 1976 ZEO 6083 Maintenance Manual page 695

24C- 1 8 ONAN MOTOR GENERATOR
PRECISION TYPE - DO NOT LINE REAM OR BORE .
ALIGN HOLE IN BEARING-- ! -7/32"
F ROM
OUTSIDE
WITH HOLE
IN BEARING BORE
A-1609
Figure 20-Crankshaft Bearing
installing the crankshaft . Oil grooves in thrust wash-
ers must face the crankshaft and washers must be flat
(not bent). The two notches on each washer must fit
over the two lock pins to prevent riding on the crank-
shaft.
NOTE:
Original front bearing uses a separate
thrust washer . Replacement front bearing is a
one piece assembly with thrust washer part of
the bearing . Do not use a separate thrust washer
when installing this replacement part . See Fig-
ures 21 and 22 .
New camshaft bearings are precision type which
do notrequire line reaming or line boring after instal-
lation . Coat the bearing with SAE20 to reduce fric
tion . Place the bearing on the crankcase over the
bearing bore with the elongated hole in proper posi-
tion and narrow section facing out (except bores
without oil holes install with bearing groove at the
top) . Be sure to start the bearing straight . Press the
front bearing in flush with the outside end of the
bearing bore . Press the rear bearing in flush with the
bottom of counterbore which received the expansion
plug.
CRANKSHAFT ENDPLAY
After the rear bearing end plate has been tight-
ened using the torque recommended in Torque
ALIGN BEARING OIL HOLES
WITH OIL HOLES IN
BEARING BORE
A-1610
Figure 21-Bearing For Rear Bearing Plate
ALIGN BEARING
NOTCHES WITH
LOCK PINS
AND MATCH
OIL HOLES
FRONT MAIN
BEARING BORE
Figure 22-Front Bearing Installation
Specifications check the crankshaft endplay as
shown in Figure 23 . If there is too much endplay (see
Specifications), remove the rear bearing end plate
and add a shim between the thrust washer and plate.
Reinstall the end plate making sure the thrust
washer and shim notches line up with the lock pins .
Torque and recheck endplay of the crankshaft .
CHECKING BEARING CLEARANCE WITH
PLASTIGAUGE
1 . Make certain that all parts are marked or iden-
tified so that they are reinstalled in their original
positions.
Figure 23-Crankshaft Endplay