A piece of the upper rack wheel broke off and fell inside the machine unknowningly. I've replaced the wheel parts, but the small piece may be inside the bottom of the machine. I can't feel or see anything, but want to know if I can remove a few parts to retrieve the pieces before any further damage is done. DW is still cleaning fine, but it makes a squeeling noise when in wash cycle. Drains and fills fine. Cleaning well. (Trying not to use it for now!) Any suggestions will be greatfully appreciated~