GMC 1976 ZEO 6083 Maintenance Manual page 696

Figure 24-Measuring Bearing Clearance
2. Place a piece of correct size Plastigauge in the
bearing cap the full width of the crankshaft rod sur-
face about 1/4 inch off center (figure 24).
3. Rotate the crank about 30° from bottom dead
center and reinstall the bearing cap; Tighten the bolts
to the torque specified at the end of this section . Do
not turn the crankshaft .
4. Remove the bearing cap. Leave the flattened
Plastigauge on the part to which it has adhered and
OIL SEALS (FIGURE 25)
PISTON ASSEMBLY
1 . Lubricate all parts with engine oil.
GEAR COVER OIL SEAL
REAR BEARING PLATE
REAR BEARING PLATE
OIL SEAL
A-1614
Figure 25-Gear Cover and Rear Bearing Plate Oil Seals
ONAN MOTOR GENERATOR
24C- 1 9
compare the widest point with the graduations on
the Plastigauge envelope to determine bearing Clear-
ance .
The bearing plate must be removed to replace the
oil seal . Drive the oil seal out fiom the inside .
Before installing the seals, fill the space between
lips with a multi-purpose grease. This will improve
sealing.
When installing the gear cover oil seal, tap the
seal inward until it is 31/32" from the mounting face
of the cover.
When installing the bearing plate oil seal, tap the
seal into the bearing plate bore to bottom against the
shoulder in the plate bore . Use a seal expander or
place a piece of shim stock around the end of the
crankshaft, when replacing the bearing plate to avoid
damaging the seal . Remove the shim stock as soon
as the plate is in place.
2. Position piston on its respective rod and install
the pin.
3 . Install the rings on the pistons starting with the
oil control ring (figure 26). Use a piston ring spreader
GEAR COVER
0112 l
MOUNTING FACE
OF GEAR COVER
'New style thin
THIS SURFACE SHOULD BE
CLEANED OF ALL OLD
OIL SEAL
open-face seal
SEALING COMPOUND BE-
dimension is
FORE INSTALLING SEAL .
'31/32"
1-7/64"
THIS SURFACE SHOULD BE
CLEANED
OF ALL OLD DRIVE OR PRESS OIL
SEALING
COMPOUND BE- SEAL TO SHOULDER
01
FORE INSTALLING SEAL . OF THE PLATE BORE