Yamaha BT1100 2002 Service Manual page 275

SHAFT DRIVE
Inspection notes
1. Investigate any unusual noises.
The following noises may indicate a mechani-
cal defect:
a. A rolling "rumble" during coasting, accelera-
tion, or deceleration, (increases with the rear
wheel speed, but does not increase with high-
er engine or transmission speeds).
Diagnosis: Possible wheel bearing damage.
b. A whining noise that varies with acceleration
and deceleration.
Diagnosis: Possible incorrect reassembly or
too little gear lash.
WARNING
Insufficient gear lash is extremely destructive
to the gear teeth. If a test ride, following
reassembly, indicates these symptoms, stop
riding immediately to minimize gear damage.
c. A slight "clunk" evident at low speed operation
(not to be confused with normal motorcycle
operation).
Diagnosis: Possible broken gear teeth.
WARNING
Stop riding immediately if broken gear teeth
are suspected. This condition could result in
the shaft drive assembly locking up, causing a
loss of control and possible injury to the rider.
6-70
CHAS