LG Tromm Grinding Noise

[btalberg]

Model Number

wm2277hw

Brand

LG

Age

More than 10 years

Our LG Tromm WM2277hw is making a grinding noise when the drum spins (see here). I thought the splines on the drum shaft might be bad, but I've replaced the rotor hub assembly and the grinding persists. I'm now convinced the problem is the motor rotor rubbing against the stator. I believe that's because the drum shaft is coming too far out through the bearing (see here). This makes it so the motor rotor doesn't sit flush and has some play to it.

I took the washer apart down the spider bracket to see if the bracket was deteriorating, but it looks okay to me. And when I spin the drum by hand, it spins smoothly, so I don't think the bearing is the problem.

Any ideas what might be going on? Does my theory that the drum shaft is coming too far through the bearing sound right? And if so, any ideas what the fix is?

Spider bracket and shaft

Shaft poking through hub assembly

 

[btalberg]

Solved it! The play caused by the drum shaft sticking all the way through the hub assembly was a red herring. The problem was the Motor Rotor Position Sensor. I ordered a new one on Amazon. I plugged it in, started the washer, and the grinding noise has gone away. It spins without issue again.

 

[Hogan773]

Solved it! The play caused by the drum shaft sticking all the way through the hub assembly was a red herring. The problem was the Motor Rotor Position Sensor. I ordered a new one on Amazon. I plugged it in, started the washer, and the grinding noise has gone away. It spins without issue again.

What was your sound? A constant grinding or intermittent metallic clicking?

Was the rotor position sensor physically touching the rotor at times or what caused the sound?

I have noted some intermittent clicking after I just did the bearings replacement and it sounds like sometimes the rotor is pinging something on the stator but sometimes it is quiet and doesn't touch at all. Weird

 

[btalberg]

I linked to a video where I captured the sound. Here it is again:

I'm not sure why it was making the noise it was making. The rotor position sensor wasn't touching the rotor. My best guess is the rotor position sensor was sending a confusing signal to start and stop spinning the rotor at a high frequency. So basically, the noise was a nasty sounding vibration (maybe).

 

[Hogan773]

Ah wow I see. Sounds like your Tromm is about to transform into a Decepticon haha

That is (luckily) not what I am hearing. Mine is physical because with the rotor installed and no power I can sometimes hear the metal "click" (like just a very brief metal to metal contact) while rotating by hand but the thing that perplexes me is that it isn't uniform or in a repeatable pattern. If there was something out of round then it would presumably scrape every single revolution.

I may just run a few more cycles and see but it is weird and I am curious. May have to go pull off the rotor one more time and just see if there is anything I am missing like a small piece of metal or something stuck in there that could stick to one of the magnets and scrape against one of the stator heads and get knocked off but then get picked up again by the magnets and do it again. I don't know how else to explain a physical scrape that is also not repeatable with rotations.....

 

[Hogan773]

The other thing I will check is whether the washer for the shaft nut is somehow warped and thus the rotor could wobble a little (although it has no apparent movement or looseness by hand)

 

[btalberg]

Bizarre. Good luck figuring it out @Hogan773!