Product review (1 stars): Kitchenaid needs to re-engineer these parts...
This is the 4th one of these that I have had to buy for my dishwasher in the past year.  The retaining clips which hold the little wheels in place become brittle in about 6 months and break off. Thus, the little wheels in the track become detached from this unit and the to dish tray can fall out and down.  Kitchenaid needs to find a different material to manufacture this part from so consumers don't have to buy two or three of them each year.