The Polaris drive system is a centrifugally actuated
variable speed belt drive unit. The drive clutch, driven
clutch, and belt make up the torque converter system.
Each clutch comes from the factory with the proper
internal components installed for its specific engine model.
Therefore, modifications or variations of components at
random are never recommended. Proper clutch setup and
adjustments of existing components must be the primary
objective in clutch operation diagnosis.

Drive Spring

The drive spring opposes the shift force generated by the
clutch weights, and determines the neutral RPM,
engagement RPM, and wether the engine RPM remains
flat, rises, or falls during shift out. When changing only the
drive spring, installing a spring with a lower pre-load rate
will result in a lower engagement RPM speed, while
installing a spring with a higher pre-load rate will result in
a higher engagement RPM.

Clutch Weight

The clutch weights generate centrifugal force as the drive
clutch rotates. The force generated changes in relation to
the engine RPM and with specified weight of each clutch
weight. When changing only the clutch weights, a lighter
weight will result in a higher engagement RPM, lower
shifting force, and higher shift out RPM. Installing heavier
weights has the opposite effect

Neutral Speed

Engine RPM when the force generated by the clutch
weights is less than the pre-load force generated by the
drive spring. In this mode, the drive clutch is disengaged.

Engagement RPM

Engine RPM when the force generated by the clutch
weights overcomes the drive spring pre-load force and the
moveable sheave begins to close or “pinch” the drive belt.
The engagement mode continues until no more belt
slippage occurs in the drive clutch. Once 100% belt
engagement is achieved, the sled will accelerate along the
low ratio line until the drive clutch up shift force overcomes
the opposing shift force generated by the driven clutch.

Shift Out Over-Rev

Engine RPM that spikes above the desired operating RPM
speed. The shift out RPM should come down to the
desired operating RPM, but never below, after the driven
clutch begins to open.

Shift Out RPM

Engine RPM at which the up shift force generated by the
drive clutch overcomes the shift force within the driven
clutch. In this mode, the drive clutch will move the belt
outwards, and the driven clutch will allow the drive belt to
be pulled down into the sheaves.

During WOT operation, the shift out RPM can be seen as
the maximum, sustained RPM displayed on the
tachometer. The shift out RPM should be the same RPM
as the recommended engine operating RPM. If the shift
out RPM is above the recommended engine operating
RPM, install heavier drive clutch weights. If the shift out
RPM is below the recommended engine operating RPM,
install lighter drive clutch weights.

The shift out RPM should remain constant during both the
upshift and back shift modes.

Driven Spring

A compression spring (Team driven / P2) or torsional
spring (Polaris P-85 driven clutch) works in conjunction
with the helix, and controls the shift rate of the driven
clutch. The spring must provide enough side pressure to
grip the belt and prevent slippage during initial
acceleration. A higher spring rate will provide more side
pressure and quicker back shifting but decreases drive
system efficiency. If too much spring tension exists, the
driven clutch will exert too much force on the belt and can
cause premature belt failure.

CAUTION

Because of the critical nature and precision balance

incorporated into the PVT system, it is absolutely

essential that no attempt at clutch disassembly and/or

repair be made without factory authorized special tools
and service procedures. Polaris recommends that only

authorized service technicians that have attended a

Polaris-sponsored service training seminar and

understand the proper procedures perform adjustments

or repairs.

7.3

PVT System

9923396 - 2007-2012 EDGE/Widetrak LX Service Manual

Back-Shifting

Back-shifting occurs when the track encounters an
increased load (demand for more torque). Back-shifting is
a function of a higher shift force within the driven clutch
than within the drive clutch. Several factors, including
riding style, snowmobile application, helix angles, and
vehicle gearing determine how efficient the drive system
back-shifts. The desired engine operating RPM should
never fall below 200 RPM when the drive system back-
shifts.

Final Gearing

The final drive gear ratio plays an important role in how
much vehicle load is transmitted back to the helix. A tall
gear ratio (lower numerical number) typically results in
lower initial vehicle acceleration, but a higher top-end
vehicle speed. A lower gear ratio (higher numerical
number) typically results in a higher initial vehicle
acceleration, but a lower top-end vehicle speed.

Choosing the proper gear ratio is important to overall drive
system performance. When deciding on which gear ratio
to use, the operator must factor in the decision where the
snowmobile will be ridden, what type of riding will be
encountered, and the level of performance the operator
hopes to achieve.

Gearing a snowmobile too low for extended high-speed
runs may cause damage to the drive belt and drive
system, while gearing a snowmobile too high for deep-
snow, mountain use may cause premature belt and clutch
wear.

Typically, it is recommended to gear the snowmobile with
a slightly higher ratio than the actual top speed the
snowmobile will ever achieve.

1:1 Shift Ratio

A 1:1 shift ratio occurs when the drive clutch and the driven
clutch are rotating at the same RPM.

The mathematical vehicle speed for a given gear ratio at
a 1:1 shift ratio is represented in the chaincase gearing
charts located in the Final Drive Chapter.

Low / High Ratio

Low ratio is the mechanical position when the drive belt is
all the way down into the drive clutch, and all the way out
on the driven clutch. High ratio represents when the drive
belt is all the way out on the drive clutch, and all the way
in on the driven clutch.

Driven Helix / Ramp

The helix cam is the primary torque feedback component
within the driven clutch, regardless of driven clutch type.
The beginning angle of the helix must transmit enough
torque feedback to the moveable sheave in order to pinch
the drive belt while minimizing belt slip. The flatter or lower
the helix angle, the more side force will be exerted on the
moveable sheave, while the steeper, or higher the helix
angle, the less side force will be exerted on the moveable
sheave.

PVT System Fastener Torques

Fastener

Torque

Note

Drive Clutch Bolt
(All Carbureted)

50 Ft.Lbs.

(68 Nm)

Re-torque after

running engine.

Drive Clutch Bolt
(All 2007 - Current
CFI)

80 Ft.Lbs.

(108 Nm)

Driven Clutch Bolt

17 Ft.Lbs.

(23 Nm)

Team Helix
Fasteners

60 - 80 In.Lbs.

(7 - 9Nm)

P2 Cover

12 Ft.Lbs.

(16 Nm)

Team Deflection
Jam Nut

110 In.Lbs.

(12 Nm)

DO NOT

OVER-TORQUE

P2 Deflection
Cam

12 Ft.Lbs.

(16 Nm)

P2 SPA
Deflection
Adjuster Screw
Lock Nut

10 Ft.Lbs.

(12Nm)

Spider

280-300 Ft.Lbs.

(380-406 Nm)

Apply Loctite 243

OR Loctite 242

with Primer N

Spider Jam Nut

290-330 Ft.Lbs.

(394-447 Nm)

Drive Clutch
Cover

100 In. Lbs.

(11 Nm)

Starter Ring gear

150-180 In.Lbs.

(1-1.2 Nm)

Apply Loctite 271

Use cross pattern

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