Thanks for the great tips Michael. Much appreciated. I dont see any warp or bend of the tri plate, it seems very flat, there is just a gap. It appears as if it's missing a washer, or the axel has separated from the motor (perhaps bad elastomer ?) creating the gap shown. Perhaps it's the elastomer that has worn away and caused the space / gap on the axel. I'll just have to work my way thru the 12+ rusted and stripped torx screws and open up the gearbox to see whats going on.
In the meantime, I ordered a new (used) gearbox and new elastomer and that should do it.
