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5.
DIAGNOSIS AND SERVICE: DRIVE BELT
AND CLUTCHES (CVT OR CONTINUOUSLY
VARIABLE TRANSMISSION)
5.1.
Performance problems such as lack of power or
failure to reach full speed may be caused by:
engine performance issues, dragging brakes, or
belt/clutch issues.
5.2.
Confirm whether the problem is internal to the
transaxle, in the brake system, or in the belt
drive and pulley system (CVT):
Transaxle
•
If one drive gear (forward or reverse) or the dif-
ferential lock fail to engage or disengage by
manually overriding the shift mechanism.
•
Problems originating in the CVT will effect travel
in both forward and reverse: The belt and
clutches act on the input shaft of the transaxle.
•
If forward or reverse gear is engaged, the
brakes released, and the vehicle is pushed, the
input shaft of the transaxle should rotate.
•
The driven pulley is visible through an air
exhaust port in the back of the belt cover. It
should rotate with the input shaft of the tran-
saxle.
•
If the driven pulley does not rotate when the
vehicle is pushed in gear, the problem lies within
the transmission, the gear shift control/cable, or
the driven pulley has come loose from the input
shaft.
Brakes
•
Complaints of "lurchy" operation are an indica-
tion that the brakes may be dragging or adjusted
too tight.
•
It is easy to check for dragging brakes by push-
ing the vehicle with the parking brake released,
or by jacking-up the back of the vehicle and
checking the wheels for ease-of rotation.
•
Refer to the "Brake" section of this manual for
service and adjustment information.
Engine
•
Engine performance issues will likely be accom-
panied by other engine-based symptoms: oil
smoke, black smoke from an overly rich condi-
tion, rough running, or poor idle quality.
•
Refer to the Engine" section of this manual for
diagnosis and repair of engine performance
issues.
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CVT
•
•
•
•
•
•
Maintenance
•
•
•
•
•
•
11
Poly Bed 4 X 2 Drive System
Gear clash can result from drive being applied to
the input shaft during shifting (at idle speed).
Possible causes of drive force being applied at
idle speed include: high idle speed, misalign-
ment between engine and transaxle, wrong belt,
damaged driving pulley or damaged driven pul-
ley.
Loss of drive (complete or slippage) may occur
because of a worn belt, wet belt / pulleys, dam-
aged pulleys.
Loss of top speed other than engine or brake
problems) may occur because of a worn belt,
wet belt / pulleys, damaged pulleys.
Most CVT diagnosis is done through simple
observation and measurement.
This is an enclosed drive system with an air filter
and a cooling fan. Loss of air-flow will cause the
CVT to over-heat, and will effect performance.
The CVT system should be inspected at 250
hour or 1 year intervals. The air filter should be
removed and inspected, and the CVT cover
should be removed for belt measurement and
inspection.
The air filter should be inspected every 50 hours
of operation.
Air filter life will vary with operating conditions. A
dusty environment will necessitate more fre-
quent maintenance of the engine and CVT air fil-
ters.
Belt life will vary with operating conditions. High
load, high ambient temperatures, dusty condi-
tions, operation on grades, and high number of
stop/start cycles are among factors that will tend
to shorten belt life.
Any change in performance noted by the opera-
tor should prompt inspection.
Any factors indicative of potential drive problems
should prompt inspection. eg.: evidence of
rodent nesting, or evidence of oil leakage from
engine or transaxle.
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