Cushman HAULER 800X Technician's Repair And Service Manual page 120

CONTINUOUSLY VARIABLE TRANSMISSION (CVT)
Read all of Section B and this section before attempting any procedure. Pay particular attention to Notices, Cautions, Warnings and Dangers.
B
Driven Clutch
The driven clutch sheaves are closed at rest which
results in the drive belt being held at the outer diameter
of the driven clutch. The driven clutch has no weights
but is held closed by a torsion spring which is joined to
the moveable sheave and a torque ramp (cam) that is
attached to the fixed sheave. The moveable sheave
slides against the cam with the three points of contact
provided by low friction 'buttons'.
As the drive belt starts to rotate, the driven clutch starts
to rotate. As the speed of the drive clutch increases and
the belt starts to climb the sheaves, the driven clutch
responds by being forced open in order to permit the belt
to ride lower in the driven clutch sheaves. The sheaves
overcome the pressure exerted by the torsion spring and
cam.
As the driven clutch slows, the belt rides lower in the
drive clutch sheaves. The driven clutch compensates by
closing in response to the torsion spring and cam.
Increased Load
When the vehicle is at governed speed and starts to
climb a grade or is subjected to other increased load
conditions, the drive belt friction is overcome by the
additional load and the belt seeks a point where it can
achieve adequate friction to overcome its slippage. The
belt moves outwards on the driven clutch which closes
due to the torsion spring moving the moveable sheave
against the torque ramps. The movement of the drive
belt overcomes some of the centrifugal force exerted by
the cams in the drive clutch. This forces the belt lower
into the drive clutch which increases the drive ratio. This
'downshifting' applies more torque to the rear axle with-
out an appreciable change to the engine speed since
the governor opens the carburetor in direct response to
the reduction in ground speed.
Equilibrium
The CVT functions because the drive and driven
clutches maintain equilibrium. Clutch sets are tuned to
the vehicle that they are designed to operate. Changes
in vehicle weight or desired performance characteristics
require that both clutches be tuned to the needs of the
vehicle and remain compatible with each other.
Removing the Drive Belt
With the vehicle on level ground, remove the drive belt
by pulling the belt upwards which will cause the driven
clutch sheaves to open and loosen the belt tension (Ref.
Fig. 2). The belt may then be rolled off the driven clutch.
Page J-2
Fuel Tank
Drive Belt Service
The drive belt will require no service unless the vehicle
has been operated in an extremely dusty or muddy loca-
tion in which case it should be washed with plain water.
If the belt becomes frayed or badly worn, it must be
replaced.
Drive Clutch Removal
Tool List
Plastic Faced Hammer ................................................1
Clutch Puller, (p/n 608429) ..........................................1
Wrench, 18 mm............................................................1
Socket, 18 mm .............................................................1
Impact Socket, 19 mm .................................................1
Impact Wrench (air or electric).....................................1
Ratchet ........................................................................1
Extension, 8"................................................................1
Thread Locking Sealant............................................AR
Torque Wrench, ft. lbs. .................................................1
To prevent burns and other possible injuries:
Disable the electrical system before attempting
to remove the drive belt to prevent the engine
from inadvertently starting.
Be sure that the engine and exhaust compo-
nents have cooled before attempting any ser-
vice.
Do not allow fingers to become trapped
between the belt and clutch sheave.
Repair and Service Manual
Drive
Clutch
Fig. 2 Removing the Drive Belt
(Ref. Fig. 3)
Starter
Qty.