Hoover DX0A 67LW3 Motor making strange noise

yes - tempting fate you are 😁

Yep I remember how 'squealy' the older hoover washing machines used to be when spinning , one of the noisiest's out there - hotpoint motors carbon brushes used to fail quick enough and very sparky in operation ... but they were very cheap a replacement set , and not too hard to fit, as long as they slid nice and freely in their holder

This reminds me of when I first started working on washing machines back in 1976. Back then, Hoover's motors were "DC" instead of AC. Their module converted the power to DC for some reason. Anyway, the carbon brushes on these motors were so hard that they literally never wore out. We used to get motors to repair that had a two or 3 mm groove worn in the commutator. This reminds me that some things can be too well-made.

Essentially, the carbon brushes didn't wear down, the armature did. Which, when you think about it, is ridiculous. They eventually changed them over to AC motors, and made the carbon brushes a lot softer. Obviously when you have two parts rubbing together you have to have one, that is much cheaper and easier to replace, that is designated to take most of the wear and tear.

The same thing applies to brake pads and the discs in cars, where the brake pads need to wear down and not the discs. And I even heard once that tarmac is used on roads, which has to be regularly replaced, because using a much harder product such as concrete would cause excess wear on the tires of cars.

We all know what's going to happen now, don't we?

Hi Andy. Yes induction motors have always been far more reliable. The lack of carbon brushes removes a major part that is subject to wear. Though if the brushes are good enough quality they do not give much trouble. For example, my Miele washing machine is about 17 years old and we have never needed to change the brushes.

I always remember being told that brushless motors just could not compete with the speeds. I think it took them a long time to be able to get them to spin fast enough. Obviously, that's changed now. However, how reliable they are is also very dependent on the quality of the components, and I'm not so sure how much more reliable most of them are specially in the cheap brands.

I would definitely say that all things being equal an induction motor is far more reliable but it's quite possible for a well made motor with carbon brushes to be far more reliable than a poorly made induction motor 🙂The other advantage, as you point out is that they are much quieter, which is a great improvement.

Inverter motors on washing machines one of the best things ever these days now. So glad that washing machine manufacturers, even on cheaper budget machines are switching over to brushless motor's now and fitting them these days. So much more reliable and quieter now than the old type carbon ones.

Clean the commutator by holding small strips of emery cloth over it and turning the armature by hand until it’s back to the copper colour and the slight ridges smoothed out.

If the brushes are not shiny-smooth try to gently file out any ridges too, but don’t change the shape of the curve as it will prevent full contact with the commutator.

Best thing is a proper comm stick Andy 😊. I’ve never used anything but a comm stone or fine emery cloth. But if you found that works then is clearly does. Like you say you don’t want too much wd-40 as you’d get quite a big flash when it started up.

Also, you don't want to get any wd-40 anywhere near the bearings, as it will strip out the grease. So WD-40 should only be sprayed onto the rag and not directly onto the commutator stop

I've ordered some emery paper anyway off Amazon that will be here in the morning.

I have cleaned in the past before with an old tooth brush sprayed with a little wd40 and dried/buffed with a clean lint free piece of cloth with my index finger , getting too course emery paper could score the brass segments where the carbon brush sits on. WD40 is flammable though , especially when still wet so you want to make sure that it is dry totally before operating the motor .

Is it something you would also recommend Andy if you didn't have any emery paper around? - or can be used instead of emery paper just to clean up the brass commutator ?

It's a little better I think. I'll put it back together and buy an emery cloth in the meantime. We have a newborn (2 days) so can't leave it apart for too long!

Does it sound a lot better now? A sheet of fine Emery cloth is dirt cheap in any hardware store or B&Q etc, but you could fire it up and see how it runs. If there's excessive sparking, you'd really need to clean it up to hopefully improve things. But if it runs OK with only a few very small sparks a fraction of a mm big it should be OK.

So once I got it at a better angle I realised there were 3 placeholder slots on each side so it allows it to slot in the wrong way, my mistake!

I've not actually got an emery cloth, is anything else suitable?

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They are the wrong way around! They should be fitted so that the curved part of the tip of the brush runs on the commutator. You have them so that the back edge is trailing.

You probably need to swap them over to the opposite side. Also try to clean the commutator as suggested with fine emery cloth.

Gave it a wipe. Sounds worse after putting them back but not sure if user error.

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I’d like to see a photo of both the brushes, where they run on the commutator.

Great photos. Very useful. The black marks from the brushes should be uniform. It should be uniformly black all along. It’s ridged, as though the brush has never bedded in.

Try my last suggestion. Also, make sure both brushes a free to move in and out inside the brush holders so that the feed through as they wear.

This is the commutator (I think). Fairly smooth on feel, odd ridge maybe.

Those brushes aren’t remotely worn. What’s the surface that touches the commutator like? They should be shiny and smooth and curved.

You could try gently rubbing the surfaces with some fine emery cloth and gently cleaning the commutator too.

Brushes off. Sound has gone.

Thanks Andy. It’s definitely something scraping and you could be right. It sounds almost metallic to me, it just makes sense to check the brushes first. I wondered if somehow the brass part of the brush holder was catching or a brush was broken.

Don't sound like brushes to me - sounds like the coil on the armature or the magnets have swollen and running against plastic on the stationary coils: - I think even with carbon brushes removed you will still get the scraping noise

Yes. That one looks ok although it could still need replacing if there’s not much else left of the brush.

What’s the other brush like?

I think it is the brush. I'm a newbie at washers but a major DIYer in that I'll give out a go. Seems an easy switch if it is the carbon brush?