If there are notches worn into the splines, replace the sub clutch hub. Also, replace the steel plates if their teeth are damaged.

Clutch Housing Finger Inspection
Damper Cam InspectionFront Forks/Rear Shock Absorber Operation Inspection
Pump the forks down and up [A] 4 or 5 times, and inspect
the smooth stroke.
If the forks do not smoothly or noise is found, inspect the
fork oil level or fork clamps (see Front Fork Oil Change in
the Suspension chapter).
Pump the rear seat down and up [A] 4 or 5 times, and
inspec ...
Shift Pedal Removal
Remove:
Shift Lever Bolt [A]
Front Footpeg Bracket Bolts [B]
If the tie-rod [C] is to be removed from the shift pedal and
the shift lever, loosen the tie-rod locknuts [D].
The front tie-rod locknut is left-hand thread.
Remove:
Shift Pedal Mounting Bolt [A]
...
Upper Fairing Assembly Disassembly
Remove:
Upper Fairing Assembly (see Upper Fairing Assembly
Removal)
Headlight (see Headlight Removal/Installation in the
Electrical System chapter)
City Light (LED) (see City Light (LED) Removal/Installation
in the Electrical System chapter)
Remove the screws [A], and separate each ...