G643 (E) Service Manual Chapter 3. Engine Mechanical System
97
IMPORTANT: Connecting rod bearings are of the
precision insert type and do not use shims for
adjustment. DO NOT FILE RODS OR ROD CAPS.
If clearances are excessive, install a new bearing.
Service bearings are available in standard size
and 0.050 mm (0.002 in.), 0.254 mm (0.010 in.),
0.508 mm (0.020 in.), undersize for use with new
and used standard size crankshafts.
Install or Connect
1
. Lubricate the cylinder walls lightly with engine oil.
2
. Make sure the piston is installed in the matching
cylinder.
3
. Connecting rod bearings.
A
. Make sure that the bearing inserts are of the
proper size.
B
. Install the bearing inserts in the connecting
rod and connecting rod cap.
C
. Lubricate the bearings with engine oil.
4
. Piston and connecting rod into the proper bore.
A
. With the connecting rod cap removed, install
J 5239 onto the connecting rod bolts
(figure 12-69).
B
. Locate the piston ring end gaps (figure 12-70).
Lubricate the piston and rings with engine oil.
Figure 12-69 Guiding Connecting Rod
C
. Without disturbing the ring end gap location,
install J 8037 over the piston.
D
. The piston must be installed so that the notch
in the piston faces the front of the engine.
E
. Place the piston in its matching bore. The
connecting rod bearing tang slots must be on
the side opposite the camshaft. Using light
taps with a hammer handle, tap the piston
down into its bore (figure 12-71). Guide the
connecting rod to the crankpin with J 5239
(figure 12-69). Hold the ring compressor
against the block until all rings have entered
the cylinder bore.
F
. Remove J 5239 from the connecting rod bolts
Figure 12-70 Piston Ring End Gap Location
Figure 12-71 Installing Piston
