Spider Indexing - Polaris 850 PRO-RMK 155 2020 Manual

BELT-TO-SHEAVE CLEARANCE
ADJUSTMENT
Belt-to-sheave clearance is an important factor when
evaluating drive clutch performance as it controls the
starting drive ratio and the position of the drive clutch
weights in relation to engine RPM.
If the clearance is too small, the drive belt will drag on the
face of the sheaves when the engine is at idle speed.
If the clearance is too large, the belt will slip during initial
engagement causing belt burning and engine bogging.
MEASUREMENT
Belt-to-Sheave Clearance
Nominal = .020 - .060 in (0.508 - 1.524 mm)
NOTICE
Technicians can fine tune belt-to-sheave clearance to
accommodate individual rider preferences. When fine
tuning belt-to-sheave clearance, it is recommended to
have a minimum of .005 in (0.127 mm) clearance when
using a new drive belt.
Belt-to-sheave clearance can be adjusted by installing a
different drive belt, or by adding or removing shims
washers located under the spider assembly.
To measure belt-to-sheave clearance, follow these steps:
1. Verify the drive clutch sheave faces are clean and
the drive belt is in good condition.
2. Push the drive belt tight against one of the drive
clutch sheaves. Measure the opposite-side gap
using a feeler gauge.
3. A slight drag should be felt when inserting the feeler
gauge between the belt and sheave face.
4. Compare the measured gap to specification.
The distance between the moveable and stationary
clutch sheaves, and
clearance, is determined by the number and
thickness of the washer (s) installed between the
spider and clutch spacer.
To increase the clearance, add or install thicker
washer (s). To decrease the clearance, remove or
install thinner washer (s). Either way, the belt-to-
sheave clearance adjustment most often requires
the spider to be "re-indexed".
9850060 R02 - 2020-2021 850 AXYS™ Long Track Snowmobile Service Manual
© Copyright Polaris Inc.
thus the belt-to-sheave

SPIDER INDEXING

NOTICE
Spider indexing affects belt-to-sheave clearance and
clutch balance. Please read all procedures before
proceeding.
1. Remove and disassemble clutch.
2. Add or remove the spider washers as required to
achieve desired belt-to-sheave clearance. For
example: If belt-to-sheave clearance is .020 in (0.51
mm) too large, removing one .020 in (0.51 mm) shim
will position the movable sheave closer to the fixed
sheave reducing belt-to-sheave clearance by .020".
3. Place the correct number of spacer washers
between the spider and clutch. The following washers
are available for fine tuning:
Drive Clutch Spacers:
5210752 - .020 in (0.51 mm)
5242981 - .025 in (0.63 mm)
5210753 - .032 in (0.81 mm)
5210754 - .050 in (1.27 mm)
q
Jam Nut
w
Spider
PVT SYSTEM
e
7
e
Spacer Washers
7.23