Lower Crankcase Preparation; Crankcase Assembly - Polaris ACE 900 2017 Service Manual

5. Install the balance shaft, placing the tooth with the
alignment dot in-line with the dot on the crankshaft
gear.

LOWER CRANKCASE PREPARATION

NOTICE
Always replace plain bearings when the crankcase or
connecting rods have been disassembled. Refer to
bearing selection procedures.
1. Remove all traces of crankcase sealant from the
crankcase mating surfaces. Inspect the surfaces
closely for nicks, burrs or damage.
2. Clean bolt hole threads to remove any oil or
crankcase sealant.
3. Inspect crankcase bearing bores. Replace the
crankcase assembly if a bearing bore is galled or if
bearing inserts have rotated in the case.
4. Be sure alignment pins are in place where used.
5. Refer to "Oil Flow Chart" at the beginning of this
chapter and trace the oil paths through the
crankcase and cylinder.
6. Flush all oil passages with solvent and then warm
soapy water. Rinse with clear, warm water and dry
with compressed air.
7. Be sure passages are clean and dry before
assembling the crankcase.
9929422 R02 - 2017-2019 ACE 900 Service Manual
© Copyright Polaris Industries Inc.
ENGINE / COOLING SYSTEM

CRANKCASE ASSEMBLY

1. Check to be sure the PTO crankshaft seal is resting
properly in the upper crankcase.
2. Align tab of new main bearings
w
shaft bearings with the slot in each bearing bore
of the lower crankcase. Press bearing inserts firmly
into place.
3. Apply Polaris PS-4 engine oil to the new bearings
installed in the lower crankcase half.
4. Clean crankcase mating surfaces to remove any oil.
5. Apply a thin, continuous film of Crankcase Sealant
(PN 2871557) to upper crankcase mating surface
Do not allow sealant to dry before assembly.
NOTICE
DO NOT block oil passages
q
and new balance
e
.
r
with crankcase sealant.
3.75
3