Pvt System Overview; General Operation; Drive Clutch Operation - Polaris ACE 900 2017 Service Manual

PVT SYSTEM OVERVIEW

GENERAL OPERATION

WARNING
All PVT maintenance or repairs should be performed by
a certified Polaris Master Service Dealer (MSD)
technician who has received the proper training and
understands the procedures outlined in this manual.
Because of the critical nature and precision
balance incorporated into the PVT components, it is
absolutely essential that no disassembly or repair
be made without factory authorized special tools
and service procedures.
The Polaris Variable Transmission (PVT) consists of
three major assemblies:
1) The Drive Clutch
2) The Driven Clutch
3) The Drive Belt
The internal components of the drive clutch and driven
clutch control engagement (initial vehicle movement),
clutch upshift and backshift. During vehicle development,
the PVT system is matched first to the engine power
curve; then to average riding conditions and the vehicle's
intended usage. Therefore, modifications or variations of
components at random are never recommended. Proper
clutch setup and careful
components must be the primary objective when
troubleshooting and tuning.
9929422 R02 - 2017-2019 ACE 900 Service Manual
© Copyright Polaris Industries Inc.

DRIVE CLUTCH OPERATION

Drive clutches primarily sense engine RPM. The two
major components which control its shifting function are
the shift weights and the coil spring. Whenever engine
RPM is increased, centrifugal force is created, causing
the shift weights to push against rollers on the moveable
sheave, which is held open by coil spring preload. When
this force becomes higher than the preload in the spring,
the outer sheave moves inward and contacts the drive
belt. This motion pinches the drive belt between the
spinning sheaves and causes it to rotate, which in turn
rotates the driven clutch.
At lower RPM, the drive belt rotates low in the drive
clutch sheaves. As engine RPM increases, centrifugal
force causes the drive belt to be forced upward on drive
clutch sheaves.
inspection of existing
PVT SYSTEM
5
5.3