How to Clean an Agitator Washing Machine

Quick Answer

To clean an agitator washer, run a dedicated 'Clean Washer' cycle or a hot water wash with two cups of white vinegar, then scrub the agitator fins and the fabric softener dispenser with a soft brush and baking soda paste. Finish with a second hot rinse cycle to flush out any remaining loosened debris.

When I show up to a house because clothes smell like a wet dog even fresh out of the dryer, nine times out of ten it's the agitator. That scrud buildup, the black waxy gunk made of old detergent, skin cells, and fabric softener, is basically a mold buffet. Ignore it long enough and you're looking at a clogged pump, a ruined drain line, or a machine that starts leaving black streaks on your whites.

GenericWasherSeverity: lowDifficulty:

Time to Fix

60–120 min

Difficulty

Parts Cost

$0 (no parts needed)

Tools Needed

White distilled vinegar, 2 cups, Baking soda, half cup

How to Clean an Agitator Washing Machine

Here's the deal: cleaning an agitator washer costs you maybe $3 in vinegar and baking soda and about an hour of your time every month or two. Skip it for a year and you're calling someone like me to snake out a drain line or swap a pump that got gunked up. I've seen brand-new machines develop serious scrud problems in under six months just from using too much liquid softener on every load.

Common Causes

Using liquid fabric softener on every single load without ever running a cleaning cycle, which lets a waxy film build up on the agitator fins over time until it's basically shellacked on.
Closing the lid immediately after every wash traps moisture in the dark and mold moves in fast, especially in the crevices where the agitator column meets the bottom of the tub.
Overdosing on detergent, particularly non-HE soap in a modern low-water machine. The excess suds can't rinse away and they dry into a sticky, gray residue that coats everything inside.
Hard water deposits combining with soap scum to form that chalky, grayish scrud layer. If you're in a hard-water area and you've never used a descaler, it builds up pretty quickly.
Never removing the fabric softener dispenser cap to clean underneath it. That little cup is basically a petri dish and most people don't even know it comes off.

Symptoms You May Notice

Black or dark gray flakes or specks showing up on your laundry right after a wash cycle, stuck to the fabric like they were glued there.
A sour, musty, or mildewy smell that hits you the moment you open the lid, even right after a cycle just finished.
Clothes don't actually smell clean when they come out, even with fresh detergent and the right settings.
The fabric softener dispenser cup is caked over, crusty, and clearly not dispensing properly anymore.
A visible grayish or brownish slime coating around the base of the agitator or along the top rim of the tub.

Tools Required for Diagnosis

White distilled vinegar, 2 cupsBaking soda, half cupOld toothbrush or narrow scrub brushMicrofiber cloths, at least 2Dry towel for wiping down drumPhillips #2 screwdriver (for agitator bolt if removing)7/16 inch socket and ratchet (for some agitator bolts)Bucket or plugged sink for soaking dispenser cap

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

Frequently Asked Questions

Can I use bleach instead of vinegar?

Yeah, bleach works great for killing mold and bacteria. Use about one cup in a hot cycle. But don't use it in the same cycle as vinegar, that combo makes toxic chlorine gas and your laundry room is probably not that big. Run bleach in one cycle, do a plain hot rinse, then you're done. Bleach is better for sanitizing, vinegar is better for dissolving mineral buildup and soap scum. Honestly if the machine is really bad, do vinegar first, rinse it out, then bleach, then another rinse. Belt and suspenders.

Why does my washer still smell after cleaning it?

If it still stinks after doing all of this, the gunk is probably between the inner and outer tub where you literally can't reach with a brush. That's where commercial cleaning tablets like Affresh or Tide Washing Machine Cleaner earn their money. They've got surfactants designed to get into that gap and break up hidden scrud. Run two or three tablets back to back on the hottest cycle your machine has. If it still smells after that, check the drain hose and pump filter, because mold loves to set up shop in there too.

How do I clean under the agitator?

Most top-load agitators come off pretty easily. Look under the fabric softener cap for a bolt, usually a 7/16 inch hex head or a Phillips. Pull that bolt out, grab the agitator with both hands, and pull straight up. It'll pop off. Once it's out you can scrub the well at the bottom of the tub and clean all the way around the agitator shaft where all kinds of nasty stuff collects. I only bother recommending this step if there's a bad smell that won't quit after two or three regular cleanings, or if you're seeing chunks of debris in the wash.

Does using more detergent keep the machine cleaner?

No, it's actually the opposite, and this is one of the most common mistakes I see. Too much detergent, especially high-sudsing regular soap in a machine that's supposed to use HE detergent, is probably the number one cause of scrud buildup. Modern machines use way less water than old ones, so extra soap just doesn't rinse out. It sits there, gets sticky, and starts trapping lint, skin cells, whatever else is in the wash. Use the recommended amount or even a little less, and switch to HE detergent if your machine calls for it.

How often should I actually be cleaning this thing?

If you use liquid fabric softener on most loads, do a cleaning cycle every month. No kidding. If you're using powder detergent only and skipping the softener, every three months is probably fine. Hard water area? Lean toward more frequent. The single best habit that costs you nothing is just leaving the lid open after every wash. That one thing cuts down how often you need to do the full vinegar-and-baking-soda treatment by a lot. I tell every customer the same thing and the ones who listen don't call me back nearly as often.

Can I use a commercial cleaner like Affresh instead of doing all this?

Absolutely, and sometimes it works better for the deep stuff. Affresh tablets run about $8 for a pack of three and they're specifically designed for washing machines. They dissolve slowly during the cycle and get into spaces that a vinegar soak doesn't always reach. I tell people to alternate: do the vinegar and baking soda DIY clean every month, then throw in an Affresh tablet every three or four months as a deeper clean. You don't have to pick one or the other.

Models Known to Experience HOW-TO-CLEAN-AGITATOR Errors

This repair applies to most Generic washers with this error code. Common model numbers include:

Whirlpool WTW4816FW, Whirlpool WTW5000DW, Maytag MVWB765FW, Maytag MVWC465HW, GE GTW335ASNWW, GE GTW485ASJWS, Amana NTW4516FW, Speed Queen TR5003WN

Written by

Mike Sullivan

Lead Appliance Repair Technician · 20 years experience

Last verified for technical accuracy on March 17, 2026