My solution is shaft collars.Slide on 2,3,4 depends on how long the lift pin is. Iinstall lynch pin to keep them from sliding off. You can find these shaft collars at a lot of places such as Tractor Supply( to expensive ) Graingers, Fastenal, Baileynet. Price from $.80 to $1.30 each. So for under 10 bucks for each implement, no more moving bushings.
Mike