Diagnosis and service: drive belt and clutches, Poly bed 4 x 2 drive system – Cub Cadet 4 x 2 Big Country - Poly Bed & Steel Bed User Manual
Page 15

Poly Bed 4 X 2 Drive System
11
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.
CVT
•
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.
Maintenance
•
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.