Product review (5 stars): Much better part than original.
This replacement kit to repair the sliding mechanism on the upper trya is considerably better built than the palstic parts I replaced and which had been broken for some time.  Installation took less than an hour although removal of the old part was challenging.  The installation instructions were fairly good and I had no problems with installing the new part.  This part was reasonably priced and delivered promptly.  The new part is metal for the support bars (versus plastic on the old) and the wheels have better bearings/supports.