Gene, it is a GSD4134, part 501. I broke the retaining clips apparently. There was only one, but it was rescued from the sump pump collection area. (whew! - and the shield like piece kept it out of the pump) So, we have "engineered" something to hold it and everything seems to be working fine. The dishwasher is technically 12 years old, but not used much by previous owner who was bachelor who ate out a lot. Thanks for trying to get me going in the right direction. I am wondering how hard it is to get a whole new piece in or if it is worth worrying with at all with the age of the dishwasher. It works great before this issue which I definitely think was the plastic film of the detergent tabs not completely dissolving.

I recently removed the float mechanism, the filter cover, and the sump cover to clean out debris (some of which was visible in the filter cover) because the dishes - especially black cooking tools had a grey film and there was small debris in the bottom of dishwasher, although most plates and glasses were cleaning up quite well. There was a lot of gummy buildup in the float mechanism and underside of all the parts. When the spray arm was removed, I noticed the "clip" holding the arm in. I pulled up and it released. There was a little bit of paper like stuff in the spray arm and it was removed and cleaned. When I put it back into the dishwasher, I could not "find" the clips to hold the spray arm down. This is necessary so that the water force pushes the collapsing tower up to the spray part on the top rack. Did I break something? It appears from the parts picture that the lower part of the spray arm (part 501) aka AP2039850 has become detached and is still in the dishwasher. how do I get this reconnected? the dishwasher runs fine, but obviously is not spraying correctly as the arm will not stay in place and extend the water up to the upper rack arm.