The two forward wheel assemblies on each side were broken. Until the new ones arrived, I did not realize that the wheel was supposed to be attached to the clip for the rack! Once I saw that, I knew that the broken wheels needed to come off. This was accomplished by removing the rail end caps to allow the old wheels to slide out. With the rail open, the new assemblies could be slid in with their attached wheels. It only remained to fasten in the sides of the clip to the rack. It was a quick fix by the standards of work of having to deal with plumbing or electrical parts. This was purely mechanical. Would recommend it to anyone as the perfect DIY effort to wring a few more years out of an old dishwasher.