internal noise

[fruit_nut]

took the bike out this morning, and discovered that it had develped a whirring noise under deceleration,(akin to apiece of cardboard stuck between the front wheel and mudgaurd).I disassembled the clutch and the final drive,but found nothing untoward.
Has anyone come across tis problem before?

 

[rattheroach]

maybe the rear wheel bearing, not certain tho.

 

[fruit_nut]

thanks rattheroach, but the bearings are only 5k old and seem to be fine.
the noise only appears when I decelerate from above 25kph. it seems that negative thrust is causing something to misalign.

 

[fruit_nut]

Found it! Snapped the pinion shaft at the nut.
Now to find out how to remove the pinion from the housing.

 

[Rusty McNeil]

Found it! Snapped the pinion shaft at the nut.
Now to find out how to remove the pinion from the housing.

Are you talking about your rear axle?:ummm:

If you are and the axle is broken then it should just slide out after loosening the pinch bolt on the caliper side.

Rusty

 

[one2dmax]

No he's talking about the main nut holding the pinion into the rear differnetial. It's easier to replace the complete rear differential since you have to get the gears as a set.

Sean

 

[Rusty McNeil]

No he's talking about the main nut holding the pinion into the rear differnetial. It's easier to replace the complete rear differential since you have to get the gears as a set.

Sean

I would have thought that a broken pinion shaft would keep the bike from even moving?????

 

[fruit_nut]

The coupling is splined, which keeps the drive engaged.
The nut which has sheared positively locates the pinion in its housing, and maintains correct end float.

 

[fruit_nut]

picked up a s/h unit from metropolitan spares, sydney,
excellent service.
I will look at repairing the old unit by drilling & tapping the broken end of the pinion shaft, and fitting a stud & nut. This may create a weak point, which, if the stud breaks, will be repairable.

 

[fasterlapdunn]

:ttiwwp:

if you get a chance can you take pics of your repair hopefully before and after

Thanks
nut

 

[fruit_nut]

sorry ive been so slow, but I bought a s/h drive unit.
I have since fiddled with the broken pinion shaft, and
found that it was very easy to drill and tap the front end of the shaft. I placed the shaft in the lathe, holding it by the spigot inner race, and using a centre starting bit to create a starting point for a drill bit.
I drilled and tapped a 5/16 unf hole approx. 20mm. deep
using only a conventional drill and tap. There appears to be enough meat in the shaft to take the threaded hole possibly to 7/16 or 10mm. This fix is yet to be tried, but I think its worth a go, maybe by starting
with a 3/8 thread and a high grade capscrew.
If it breaks it is easily removed and taken up a size.
(the thrust bearing must be removed from the shaft,
it is in 3 pieces)
If you can do this exercise yourself, it is virtually cost free.