Chapter Iii Repair And Maintenance Of Vehicle Body; Section 1 Rear Driving Gearcase And Driving Shaft; (I)Trouble; (Ii)Inspection - ATV 250 Service Manual

Chapter III Repair and Maintenance of Vehicle body

Section 1Rear Driving Gear Case and Driving Shaft

(I)Trouble

.Trouble judging guidance
Performance
1.When the vehicle accelerates, decelerates or is in idle
start, there appears stop or irregular run-out with abnormal
noise (pay attention not to confuse with trouble of engine)
2.The vehcicle sounds obvisous boom at low speed,and
"Wu Wu"sound when decelerating or accelerating. Or there is
regular snap from the case body.
3.The transmission shaft jams and the rear wheel can not
rotate.
Caution
The reason "A","B","C"are very difficult to judage ,The performance is very subtle. And it's very
duifficult to distignguish them form normal operating noise. If you doubt it and think these components
have been damaged, remove them for special inspection.

(II)Inspection

1.Check abnormal noise:
Following noise may indicates mechanism trouble
a.Boom when sliding, accelerating or decelerating.The noise is direct ration with speed of rear wheel,
but not direct ration with higher engine speed and transmission case speed.
b.Noise "Wu Wu ".The noise is different when accerating or decelerating.
Judgement:May be incorrect assembly and too small teeth clearance.
Caution:
It is very easy to damage the gear if the teech clearance is too small. If this condition happens in trial
driving after reassembly, you should stop driving immediately to minimized the damage of gear.
c.There is light snap when runing at low speed.
Caution:
This noise must be distinguished from normal operating noise of machine.
Judgement: It is possible that the teeth of gear crack.
Warning
If you doubt that the gear teeth crack, should stop driving immediately.Because this may cease that
the transmitting components are jamed by gear fragment and lose control of vehicle, then may damage the
driver.
2.Check following condition:
a. Drain out the lubricating oil
If there is a great deal of metal or metal corpuscle on the position of oil draining screw plug,it is needed
Possible reason
A.Damaged bearing
B.Improper clearance
C.Damaged gear
D.Driving shaft breaks
E.Gear teeth break
F.Jam caused by shortage of lubricating oil
G.The gear is jamed by foreign matter
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