This is the third time the ice bucket has had to be replaced

The usual demise of these units freezing up occurs from air infiltration through the dispenser flap. This causes ice in the bottom of the bucket to weld together, making the augur strain to grind up the blockage. This in turn strips the drive bar, etc. I would replace the fountain ice door assembly along with the ice motor parts. I always use new seals at the top where the drive rod sits. I would also suspect ice door damper is staying open.too much and catching cubes. My last ice in door had a slightly worn damper-delay (perhaps adding grease to the damper would slow it down) but I replaced it and could see another full second before shut. Matt Ace technician