The upper arm fell off and the plastic screw melted. I am not sure what part the screw is called but that is what I need.
Answer Viriginia, if it is the upper arm that is underneath the top rack you'll need to replace the arm hub which is in the spray arm and hub kit part number WD35X10055 and also check the spray arm conduit WD12X10110. If it is the very top spray arm (above the rack) you'll need to check and replace the bearing WD01X10209 and screw WD02X10109. Hope this helps you. Thanks!