David W Russellville , AR March 03, 2017 Appliance: Whirlpool Dishwasher DU920PFGZ3 Whirlpool Dishwasher Du920pfgz3: Rusting lower dishwaser rack. How to replace Lower Dishwasher Rack Assembly. Purchased a new one from AppliancePartsPros.com and installed the rack. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes