Crankcase & Bearing Assembly; Crankcase Bearing Inspection - Polaris 2009 Trail Boss 330 Service Manual

CRANKSHAFT
MAIN BEARING INSPECTION
1. Inspect the crankshaft main bearings.
NOTE: Due to extremely close tolerances and
minimal wear, the bearings must be inspected
visually, and by feel. Look for signs of discoloration,
scoring or galling. Turn the outer race of each bearing.
The bearings should turn smoothly and quietly. The
inner race of each bearing should fit tightly in the
crankshaft. The outer race should be firm with
minimal side to side movement and no detectable up
and down movement.
2. Replace bearings if they fail visual inspection.
CONNECTING ROD BEARING
INSPECTION
1. Inspect bearing inserts for unusual wear, peeling,
scoring, damage etc. Replace as necessary.
NOTE: If one insert requires replacement, replace
both connecting rod bearing inserts as a set.
CONNECTING ROD BEARING
CLEARANCE INSPECTION
1. Clean all oil from bearing inserts and crank pin.
2. Place a strip of Plastigauge
width of the crank pin.
3. Install the connecting rod and bearing cap in the
correct orientation.
4. Torque the rod nuts to specification.
Rod Nut Torque:
29-33 ft. lbs. (39-45 Nm)
5. Remove the bearing cap being careful not to
disturb the Plastigauge
6. Use the measuring scale on the Plastigauge
wrapper to measure the thickness of the
®
Plastigauge . The rod must not turn during
this procedure.
®
across the complete
®
.
®
NOTE: Use the widest part of the Plastigauge
determine the oil clearance.
Connecting Rod To Crankshaft Clearance:
Std: .0007-.0021 (.019-.053 mm)
Limit: .0026 (.065 mm)
7. If oil clearance is not within specification, install
new rod bearings and recheck the oil clearance.
8. If service limit is still exceeded, determine if the
crankshaft or connecting rod needs to be
replaced per Crankshaft
Connecting Rod Inspection.
9. At completion of measurement procedure;
remove all traces of Plastigauge
and crankshaft.
CRANKCASE BEARING
INSPECTION
1. Inspect the crankshaft main bearing in the MAG
side crankcase.
NOTE: Due to extremely close tolerances and
minimal side wear, the bearing must be inspected
visually and by feel. Look for signs of discoloration,
scoring or galling. Turn the inner race of bearing. The
bearing should turn smoothly and quietly. The outer
race should fit tightly in the crankcase. The inner race
should be firm with minimal side to side movement
and no detectable up and down movement.
2. To remove crankshaft bearing, use a blind hole
bearing puller.
NOTE: Bearings are stressed during the removal
procedure and should not be re-used
ENGINE
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to
Inspection and
®
from bearing
3.31