Raymond P Quaker Hill , CT November 22, 2019 Appliance: Whirlpool Dishwasher, Built-In/Undercounter WDT720PADW0 Whirlpool Dishwasher Wdt720padw0: Top tray sag wheeler was fatigued. How to replace Upper Dishrack Roller Assembly. Ordered part and installed. Easy fix. No tools required. 12 minutes max Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes