Even if the retainer spring is worn out or broken, if the clutch free play is properly adjusted the fork can't move out of position. If the ball is worn out or broken off, it's time to remove the transmission and maybe the bellhousing and replace the pivot ball. Later ones installed from the back of the bellhousing with a big Allen wrench- - -not sure about yours.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!