Drive System Terminology; System Overview; Drive Spring; Clutch Weight - Polaris 340 CLASSIC 2006 Manual

DRIVE SYSTEM TERMINOLOGY

SYSTEM OVERVIEW

CAUTION
All clutch maintenance repairs must be performed only
by an authorized Polaris service technician who has at-
tended a Polaris sponsored service training seminar
and understands the proper procedures as outlined in
this manual. Because of the critical nature and preci-
sion balance incorporated into the drive clutch, it is ab-
solutely essential that no attempt at clutch disassembly
and/or repair be made without factory authorized spe-
cial tools and service procedures. Any unauthorized
modifications to clutches, such as adding or removing
weights, will void the warranty
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 OVERREV

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 clutch) 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.
CLUTCHING
7.7