Connecting Rod/Piston Assembly - MerCruiser GM4 Service Manual

6. If the clearance exceeds specifications, select a
new, correct size bearing and measure the clear-
ance.
Be sure to check what size bearing is being re-
moved in order to determine proper replacement
size bearing. If clearance cannot be brought to
within specifications, the crankpin will have to be
ground undersize. If the crankpin is already at
maximum undersize, replace crankshaft.
7. Coat the bearing surface with oil, install the rod
cap and torque nuts to 45 lb. ft. (61 N·m).
8. When all connecting rod bearings have been in-
stalled, tap each rod lightly (parallel to the crank-
pin) to make sure they have clearance.
9. Measure all connecting rod side clearances be-
tween connecting rod caps as shown - .006-.014
(0.152-0.356).
a - Take Measurement Here
Index
3A - 32 - ENGINES
Connecting Rod/Piston
Assembly
Removal
1. With oil, pan oil pump and cylinder head removed,
use a ridge reamer to remove any ridge and/or
deposits from upper end of cylinder bore
IMPORTANT: Before ridge and/or deposits are re-
moved, turn crankshaft until piston is at bottom
of stroke and place a cloth on top of piston to col-
lect cuttings. After ridge and/or deposits are re-
moved, turn crankshaft until piston is at top of
stroke, then remove cloth and cuttings.
2. Inspect and mark connecting rods and bearing
caps.
3. Remove connecting rod cap and install connect-
ing rod bolt guide (3/8-24) on bolts. Push connect-
ing rod and piston assembly out of top of cylinder
block.
NOTE: It will be necessary to turn crankshaft slightly
to disconnect and remove some connecting rod and
piston assemblies.
a
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a - Connecting Rod Bolt Guide (3/8-24)
(J-5239)
a
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90-816462 2-695