Yamaha BEARTRACKER YFM250XC, Service Manual

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DRIV
FINAL DRIVE GEAR AND DRIVE SHAFT
Inspection notes
1.Investigate any unusual noises
*********************************
The following “Noises” may indicate a
machanical problem:
● A “rolling rumble” noise during coasting,
acceleration, or deceleration. The noise
increases with rear wheel speed, but it
does not increase with higher engine or
transmission speeds.
Diagnosis: Possible wheel bearing dam-
age.
● A “whining” noise that varies with accel-
eration and deceleration.
Diagnosis: Possible incorrect reassembly,
too-little gear lash.
CAUTION:
Too-little gear lash is extremely destructive
to the gear teeth. If a test ride following
reassembly indicates this condition, stop
riding immediately to minimize gear dam-
age.
●
A slight “thunk” evident at low speed
operation.
This noise must be distinguished from
normal machine operation.
Diagnosis: Possible broken gear teeth.
WARNING
Stop riding immediately if broken gear
teeth are suspected. This condition could
result in a locking-up of the shaft drive
assembly, causing loss of control of the
ATV and possible injury to the rider.
*********************************
2.Inspect:
●
Drained oil
Drain plug shows large amount of metal.
Particles
→
Check bearing fur seizure.
NOTE:
A small amount of metal particles in the oil
is normal.
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