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 InspectionIdle Speed Control Valve Actuator Resistance Inspection
Turn the ignition switch to OFF.
Remove the air cleaner housing (see Air Cleaner Housing
Removal in the Fuel System (DFI) chapter).
Disconnect the idle speed control valve actuator connector
[A].
Connect a digital meter to the idle speed control valve
actuator connector [A]
...
Spring Preload Adjustment
Remove the rear shock absorber from the frame (see
Rear Shock Absorber Removal).
Loosen the locknut and turn out the adjusting nut to free
the spring.
Special Tools - Hook Wrench T=3.2 R37: 57001-1539
Hook Wrench R=35: 57001-1580
To adjust the spring preload, turn in the adjusting n ...
Cam Wear Inspection
Remove the camshafts (see Camshaft Removal).
Measure the height [A] of each cam with a micrometer.
If the cams are worn down past the service limit, replace
the camshaft.
Cam Height
Standard:
Exhaust 35.043 35.157 mm
(1.3796 1.3841 in.)
Intake 38.243 38.357 mm
(1.5056 1.5101 in. ...