How to Replace 9742945 Dishwasher Wash Arm Retainer Nut on Whirlpool Dishwashers — Step-by-Step

Your Whirlpool dishwasher's lower wash arm is wobbling or spinning freely during cycles, and you've traced the problem to that small threaded nut in the center of the tub floor. The wash arm retainer nut (part 9742945) might seem insignificant, but when it loosens or cracks, your dishes don't get clean because water pressure drops drastically. This direct-fit replacement works across dozens of Whirlpool, KitchenAid, Kenmore, and Maytag models including the DU925SCGB series and DU1000CGB series.

What You Need Before Starting

This is one of the easiest dishwasher repairs you'll tackle. You don't need specialized tools or disassembly experience.

• Flathead screwdriver (for prying the old nut if it's stuck)
• Towel (to catch any remaining water)
• Replacement 9742945 retainer nut

Estimated Time: 10-15 minutes

Difficulty: Easy

Safety First

Disconnect power to your dishwasher at the circuit breaker before starting. While this repair doesn't involve electrical work, you'll be working inside the tub where wiring connections exist underneath. There's typically residual water in the bottom of the tub even after a cycle completes, so have that towel ready to soak up a few tablespoons of water around the drain area.

Step 1: Remove the Lower Dish Rack

Pull out the lower dish rack completely and set it aside. This gives you clear access to the spray arm assembly at the bottom of the tub. You'll see the wash arm sitting on a hub in the center of the tub floor with the retainer nut holding it in place.

Step 2: Lift Off the Lower Wash Arm

Grab the lower wash arm and lift it straight up off the mounting hub. It should come right off since the retainer nut is either loose or you're replacing it. If there's resistance, wiggle it gently while pulling upward. Set the wash arm aside on a clean towel.

Step 3: Remove the Old Retainer Nut

Turn the old retainer nut counterclockwise to unscrew it from the hub. Most Whirlpool models use a hand-tighten design with ridges on the nut's edge for grip. If it's stuck from mineral buildup, use a flathead screwdriver to carefully wedge under one edge and break the seal, then continue unscrewing by hand. Once removed, check the hub threads for debris or calcium deposits and wipe clean with a damp cloth.

Step 4: Install the New 9742945 Retainer Nut

Thread the new retainer nut onto the hub clockwise. Hand-tighten it firmly, but don't overtighten—these are plastic threads that can strip if you force them. The nut should sit flush against the hub base when properly seated. You want it snug enough that the wash arm has minimal vertical play but can still rotate freely.

Step 5: Reinstall the Wash Arm and Test

Place the lower wash arm back onto the hub, aligning the center hole over the retainer nut. Give it a spin to make sure it rotates smoothly without wobbling. The arm should move with light resistance from water pressure but shouldn't flop around loosely. Slide the lower rack back in and restore power to the dishwasher.

Testing After Installation

Run a rinse cycle and listen for the wash arm spinning. Open the door mid-cycle (after canceling) and verify the arm hasn't loosened. You should see consistent spray patterns hitting all areas of the lower rack. If the arm still wobbles, remove it and check that the retainer nut is fully tightened and the hub threads aren't damaged. Models like the DU925SCGB0, DU925SCGQ2, and DU931SCGB0 all use this same retainer design, so the fit should be exact.

Frequently Asked Questions

Can I reuse the old retainer nut if it looks okay?

Not recommended. If it came loose once, the threads are likely worn or the plastic has fatigued. A $15 replacement prevents future wash arm failures and poor cleaning performance. The 9742945 is a direct OEM-quality replacement that'll last years.

Why does this nut keep coming loose on my dishwasher?

Hard water buildup on the threads prevents proper tightening, or you might be dealing with a cracked hub underneath the retainer nut. Clean the threads thoroughly before installing the new nut. If it loosens again within a few cycles, the hub itself may need replacement, which requires more extensive disassembly.

Will this part fit my KitchenAid or Kenmore dishwasher?

Yes, part 9742945 replaces WP9742945, AP6013836, and PS11747063 across Whirlpool-manufactured dishwashers sold under multiple brand names. Check your model number against the compatibility list—if you see models like DU1000CGQ1 or others in the DU series, you're good to go.