Customer Questions and Answers for Idler Roller by Whirlpool

William, You're on the right track, A rumbling noise in a dryer is usually due to a worn out roller assembly WPW10177428 or idler pulley WP35001086 . Both assemblies are subjected to heat and dust, and fail on occasion. In your case, you'll need to remove: power to the dryer, the top, and the front panel, to investigate the possible faulty parts. Thanks and Good Luck