EZ-GO ST 4X4, Technician'S Repair And Service Manual

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E
Page E-1
Repair and Service Manual
Read all of Section B and this section before attempting any procedure. Pay particular attention to all Notes, Cautions and Warnings
GENERAL
Power transmission from the engine to the rear axle is by
means of a continuously variable transmission (CVT).
The CVT consists of two matched clutch units joined by a
drive belt (Ref Fig. 1 on page E-1). The engine mounted
drive clutch is a centrifugal unit that responds to engine
speed and the rear axle mounted driven clutch is a load
sensing unit.
CLUTCHES
Drive Clutch
When the accelerator is depressed, the engine speed is
increased which causes the cams (weights) within the
centrifugal drive clutch to move outwards and force the
moveable sheave inwards. The drive belt is engaged by
the clutch sheaves and begins to rotate.
As the engine speed continues to rise, the drive clutch
sheave continues to move inwards forcing the drive belt
to the outer diameter of the drive clutch sheaves which
increases the speed of the belt. As the drive clutch
sheaves close, the driven clutch sheaves are forced
open by the belt as it rises in the drive clutch. The ratio is
greatly decreased and provides maximum speed.
When the accelerator is released, the engine speed is
decreased and the cams exert less pressure on the
moveable sheave which is forced outwards against the
cams by a compression spring. The drive belt disen-
gages from the clutch sheave when engine speed is
reduced to the point where the cams exert less force
than the spring.
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 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 fric-
tion ‘buttons’.
Fig. 1 Continuously Variable Transmission System (CVT)
.
Drive Belt
Drive Clutch
Driven Clutch
CVT Cover
CONTINUOUSLY VARIABLE TRANSMISSION (CVT)