Well, I can answer my own question now having rebuilt the gearbox. The arrow has no bearing on the direction of rotation since it is radial. (Still not sure what it's for) Insure that the various washers are replaced exactly as found as they determine the clearances. Don't try to clean up and reuse seized parts as I did. They will only seize up again! Buy and fit new parts. Oh, and take care not to lose the ball bearing and spring, part of the change mechanism, when taking it apart.
Roger
September 2008
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