Towel or sponge
Use it for: To soak up leftover water in the bottom of the tub and keep parts from slipping out of your hands.
Shop towels for appliance repairDishwasher repair
How to Replace a Dishwasher Lower Spray Arm
To replace a dishwasher lower spray arm, pull out the lower rack, remove the old spray arm from its center mount, snap or twist the new one into place, and make sure it spins freely before running a short wash cycle.
A worn, split, clogged, or warped lower spray arm can cause poor cleaning, thumping, or grinding as it hits dishes or stops turning. This is usually a straightforward repair as long as the new part matches your dishwasher and the center mount is not damaged.
Before you start: Match the replacement part to your exact dishwasher before ordering.
Safety first
- Make sure the dishwasher is off before putting your hands inside the tub.
- Wear gloves if the old spray arm is cracked or if there are sharp edges around the rack or sump area.
- Do not force plastic parts. If a retainer will not release, recheck how it is attached before prying harder.
- Keep small caps, clips, and washers together so they do not fall into the pump area.
Tools you may need
Small soft brush or old toothbrush
Use it for: To clean debris from the spray arm mount and nearby filter area before installing the new part.
Find a small cleaning brush
Needle nose pliers
Use it for: Helpful if a retaining clip or stubborn spray arm cap is hard to grip.
Shop needle-nose pliers
Work gloves
Use it for: To protect your hands from sharp edges around the rack, filter area, or broken plastic.
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Step-by-step fix
Step 1: Confirm the lower spray arm is the problem
- Open the dishwasher and slide out the lower rack.
- Look at the lower spray arm for cracks, melted spots, loose pieces, heavy mineral buildup, or bent sections that can hit dishes or the tub.
- Spin the spray arm by hand. It should turn smoothly without wobbling badly or scraping.
- Check that the spray holes are not packed with food or hard water scale. If the arm is intact and only dirty, cleaning may solve the problem without replacement.
If it works: You have clear signs the lower spray arm is damaged, badly worn, or not turning properly.
If it doesn’t: If the spray arm looks solid and spins normally, clean the holes and filter first, then retest the dishwasher before ordering parts.
Stop if:
- The center support, pump cover, or spray arm mount is cracked or broken instead of the spray arm itself.
- You find melted plastic, burnt wiring smell, or other signs of a larger internal problem.
Step 2: Set up the dishwasher and remove the lower rack
- Turn off the dishwasher at the control panel so it cannot start while you are working.
- If there is standing water in the bottom, soak up enough to keep the work area clear.
- Pull the lower rack all the way out. Lift it off the track stops if needed and set it aside.
- Clear out any loose debris around the spray arm so nothing falls into the mount during removal.
If it works: You have open access to the lower spray arm and the area around its mount.
If it doesn’t: If the rack will not come out easily, stop forcing it and check for rack stop clips or dishes catching on the door.
Stop if:
- The rack rails, tub bottom, or spray arm area has sharp broken pieces that make the repair unsafe until cleaned up.
Step 3: Remove the old lower spray arm
- Grip the spray arm near the center hub, not just at one end.
- Lift, twist, unclip, or unscrew the spray arm depending on how it is attached. Many lower spray arms either snap onto the mount or release with a center cap.
- Keep any washer, cap, or retainer that comes off with the old arm so you can compare it to the new part.
- Once removed, inspect the underside of the old spray arm and the center mount for wear, cracks, or debris.
If it works: The old lower spray arm is off and the mounting area is visible.
If it doesn’t: If the spray arm will not release, compare the center connection carefully and look for a hidden cap or retainer rather than prying harder.
Stop if:
- The mounting post or hub comes apart, is cracked, or is too damaged to hold a new spray arm securely.
Step 4: Clean the mount and compare the new part
- Wipe the mounting post and surrounding sump area with a towel.
- Use a small brush to remove food debris or scale from the mount and water feed opening.
- Set the old and new spray arms side by side and compare the hub shape, length, and locking style.
- Move the new spray arm by hand and make sure there are no shipping clips, packing pieces, or molded plastic flash blocking movement.
If it works: The mounting area is clean and the new spray arm matches the old one closely enough to install.
If it doesn’t: If the new part does not match the hub or overall shape, pause and verify fit using your dishwasher model information before installing it.
Stop if:
- The replacement part clearly does not fit your dishwasher or uses a different mounting style.
Step 5: Install the new lower spray arm
- Place the new spray arm onto the center mount in the same orientation as the old one.
- Press, twist, clip, or secure the center retainer until the arm seats fully.
- Reinstall any cap, washer, or retainer that belongs with the assembly.
- Spin the new spray arm by hand. It should rotate freely and sit level without popping back off.
- Reinstall the lower rack and make sure nothing in the rack hangs down into the spray arm path.
If it works: The new lower spray arm is installed securely and spins freely by hand.
If it doesn’t: If the arm rubs, wobbles, or lifts off the mount, remove it and reseat it before running the dishwasher.
Stop if:
- The spray arm cannot lock in place or keeps falling off even though the part appears correct.
Step 6: Run a short cycle and make sure the repair holds
- Run a short wash or rinse cycle with the dishwasher mostly empty.
- Listen for the earlier grinding, thumping, or scraping noise to make sure it is gone.
- After a few minutes, pause the cycle carefully and check whether the spray arm has changed position, which suggests it is turning during operation.
- At the end of the cycle, inspect the bottom of the tub and the lower rack area for loose parts or signs the arm hit dishes.
If it works: The dishwasher runs normally, the lower spray arm stays attached, and the original cleaning or noise problem is improved.
If it doesn’t: If the noise or poor cleaning continues, inspect dish loading, the upper spray arm, filters, and the lower spray arm mount for a different root cause.
Stop if:
- The new spray arm comes loose during the cycle, strikes the tub, or the dishwasher leaks or makes a severe mechanical noise.
Replacement Parts
Find a dishwasher lower spray arm on Amazon
Match the replacement part to your exact dishwasher before ordering.
As an Amazon Associate I earn from qualifying purchases. Repair Riot may earn a commission at no extra cost to you.
Verify the repair
- The new lower spray arm is fully seated on the center mount.
- The spray arm spins freely by hand with the lower rack installed.
- No dishes or rack parts hang down into the spray arm path.
- A short cycle finishes without scraping, thumping, or the spray arm coming loose.
- Cleaning performance at the lower rack improves compared with before the repair.
FAQ
Can I clean the lower spray arm instead of replacing it?
Yes, if it is only clogged. If the spray holes are blocked but the arm is not cracked, warped, or loose, cleaning may be enough. Replace it if it is damaged or no longer stays secure on the mount.
Why does the lower spray arm make a thumping or grinding noise?
It often happens when the arm is warped, cracked, loose at the hub, or hitting a tall item in the lower rack. A damaged arm can also wobble and scrape as it turns.
Do I need to shut off water or power at the breaker for this repair?
For this simple inside-the-tub replacement, turning the dishwasher off at the controls is usually enough because you are not opening wiring or water connections. If you are unsure or the machine may start unexpectedly, shut off power before working.
How do I know I ordered the right lower spray arm?
Match the replacement to your exact dishwasher model and compare the hub style, length, and overall shape to the old part before installation.
What if the new spray arm still will not spin?
Check for dishes blocking it, debris in the spray holes, a damaged center mount, or a water flow problem from a clogged filter or wash system issue. The spray arm itself may not be the only cause.