Whirlpool Dishwasher Wash Arm Retainer Nut Parts — Models & Compatibility

That rattling noise during the wash cycle? If your Whirlpool dishwasher's spray arm is spinning erratically or not spinning at all, the retainer nut holding it in place has likely cracked or loosened. The 9742945 wash arm retainer nut is a critical component that secures the lower spray arm to the pump housing, ensuring proper water distribution across all rack levels.

This replacement part (also known as WP9742945) works across multiple Whirlpool brands including KitchenAid, Kenmore, and Maytag dishwashers. It's compatible with over 20 models in the DU900 and DU1000 series, making it one of the most universally-needed dishwasher components.

Is This the Right Part for Your Model?

Before ordering, you'll need to verify your dishwasher's model number. Open the door and look along the top edge of the door frame or on the side panel — you'll find a white or silver sticker with the model number starting with "DU" followed by numbers. Common compatible models include DU925SCGB0, DU925SCGB1, DU925SCGB2, DU925SCGQ0, DU931SCGB0, DU1000CGB1, and dozens of others in these series.

If your model number starts with DU900 or DU1000 and was manufactured by Whirlpool, KitchenAid, Kenmore, or Maytag, this retainer nut will fit. The part replaces obsolete numbers 747435, AP6013836, and PS11747063.

About This Replacement Part

The wash arm retainer nut is a threaded plastic fastener that screws onto the pump housing stem to hold the lower spray arm assembly in place. During each wash cycle, this component experiences constant vibration and water pressure as the spray arm rotates. Over time, the plastic threads wear down or the nut can crack from mineral buildup or impact from dishes falling into the lower rack.

When this nut fails, you'll notice the spray arm wobbling, spinning irregularly, or completely detaching during the cycle. Water won't reach the upper rack properly, leaving dishes dirty after a full wash. Some users report hearing a loud rattling or grinding sound as the loose spray arm bounces against the dishwasher tub.

Replacement is straightforward — you don't need special tools. Remove the lower dish rack, unscrew the old retainer nut by turning counterclockwise, lift out the spray arm, then reverse the process with the new part. The entire repair takes about five minutes and doesn't require disconnecting power or water lines.

Cross-Brand Compatibility

This retainer nut works across Whirlpool's family of dishwasher brands because they share the same pump and spray arm design. Whether your machine carries the Whirlpool, KitchenAid, Kenmore (manufactured by Whirlpool), or Maytag nameplate, the mounting hardware is identical. That's why part number 9742945 supersedes multiple older part numbers — Whirlpool consolidated these components for easier service.

The gray plastic construction matches OEM specifications, so it'll fit exactly like the original part that came with your dishwasher. At $14.99, it's a cost-effective fix that prevents more expensive repairs down the line. A loose spray arm can damage the pump seal or crack the spray arm itself if left unrepaired.