Separate the crankcase (page 11-4).
Remove the primary shaft from the left crankcase.
Installation is in the reverse order of removal.
Inspect the primary shaft for wear or damage.
Replace the primary shaft if necessary.
Turn the inner race of each bearing with your finger.
The bearings should turn smoothly and quietly.
Also check that the bearing outer race fits tightly in the crankcase.
Remove and discard the bearings if the races do not turn smoothly, quietly, or if they fit loosely in the crankcase (page 11-25).