Use a gauge to measure the clearance between fork pin and the slot on the selector drum.
If the service limit is exceeded, determine which part must be replaced by comparing these dimensions with those of new components (sect. 3 - 1.1, Gearbox).
Also check the wear on the drum support pins; these must not show any signs of scoring, burrs, or deformation.
Turn the drum in the crankcase to establish the extent of radial play. If play is excessive, change whichever part is most worn.


Inspection of the gear selector forks
Reassembly of the gearbox shaftsRemoval of the timing gears
Slide out driving gear (a) of timing gear pair (13) and remove the woodruff
key (14).
Relieve the staking on the lock washer (12) of the nut (11).
Restrain the driven timing gear by inserting a pin in one of the holes, and
unscrew the nut (11).
Remove the nut (11), washer (12) ...
Refitting the timing belt driveshaft pulleys
To fit the circlip (10) in the driveshaft seat, use the tool code 88713.2834.
Install the inner spacer (17) on the driveshaft, taking care to align the
notch in the spacer with the slot for the woodruff
key.
Fit the first woodruff key (16) on the timing belt driveshaft.
Locate the ...
Gearbox shafts
Shim, thickness 1
Gearbox primary shaft
Shim, thickness 0.5
Needle roller bearing
5Th speed driving gear
Splined washer, thickness 0.5
Circlip
3Rd- 4th speed driving gear
6Th speed driving gear
2Nd speed driving gear
Shim, thickness 1.8
Splined washer, thickness 0.5
Sp ...