Kenmore Dryer Humming

[ifbinary]

Hello there appliantologists!  I have a technical question for your enlightened minds.

I have a 10 year old Sears Canada - Kenmore clothes dryer, model 970-C84072-00, that is starting to sound a little angry. Over the last couple weeks this battle hardened veteran of the dryer wars has slowly started becoming louder and louder, while yet still drying like the champion he/she is/was. The machine will start off its cycle sounding normal, happily tumbling away, however about 1-2 minutes into its cycle a hum begans, quiet at first, and slowly growing into a roar. Basically it just sounds as if the normal dryer sound is slowly ramping up the decibels. Running it with an empty drum makes no difference, turning heat up/down/off also makes no difference in the sound. There is no thumping, screeching, squeeking or grinding..just a slow hum/growl increasing in volume. One thing to note the drum does appear to be harder to turn by hand when it is off/empty.

With the expertise of an untrained battlefield medic' assistant, I figured some quick field exploratory surgery couldn't hurt. Hear is what I found:

• Belt appears to have lite wear, but is not frayed anywhere.
• the felt and teflon on the glides are not worn, and other than some lite lint on the felt, appear fine
• taking off the belt and rotating the drum manually, the rear drum bearing motion feels smooth, with no resistance or noise
• manually rotating the motor, there is some slight resistance and can hear what sounds likes brushes, unsure if this is a brushless motor or not?
• Fan was clean of debris and undamaged

Now, I couldnt find any information online regarding this unit, even checking parts sites the model number just does not want to be located (maybe this unit was a possible spy, good ol' false identity and all). So, I finally got ahold of someone at Sears US (wow Sears still exists in the states?) and after some lengthy searching this fine individual was able to locate some applicable part #'s.

Here is what they recommened:

• Motor w/ pully - p/n 13160100
• Idling Arm w/ wheel - p/n 131863000
• Belt - p/n 134163400
• Spring - p/n 131601000
• Drum Support Bearing - p/n 131825900
• Rear Bearing Kit - p/n 5303281153

 

Wondering, if possible, for some sage advice from all the experts here on what you think the issue I may have, or more trouble shooting steps you can recommend to determine the right part to replace. If a recording of the audio would help I can easily grab that and post a link. 

 

Many thanks in advance!

J

[ifbinary]

Here's a link to what it sounds like right from hitting start. Noise begins around the 1 minute mark and ramps up from there.

 

https://drive.google.com/open?id=1FQrn_HBblLXiRjCQ_xsKkfRImJUORJDp

[Quick]

@ifbinary  My first thought is the idler area. This appears to be a Frigidaire Laundry Center? Remove the access plate at the back of the dryer revealing the idler and spring  and motor. You may at your own risk move around and manipulate the idler and spring while it's running and see if any difference is made in the sound.  (No brushes on the motor.

[16345Ed]

I’d check rear bearing...

[Budget Appliance Repair]

Sounds to me like the vibration you get from a cracked blower wheel - inspect the center hub of the blower wheel for any cracks.

If you can get the belt off and run just the motor and still get the noise then that will prove that it is the motor or blower wheel, (My bet is on the blower wheel - I've had the standard ones do a very similar noise, haven't seen it on the laundry center style but that is the most likely cause).

[ifbinary]

Thanks everyone for your replies.

So after removing the back panel I removed the spring so that the motor was not turning the belt and drum, and the noise does go away.

Also when i manipulate the metal arm (idler arm?) towards the right (denoted with arrow in picture) when the motor is driving the belt, the noise also goes away. I'm assuming this is loosening the tension? I did look at the blower wheel yesterday when i had the unit taken apart yesterday and it did appear fine to me, no noticable cracks that I could see but can do it again for a closer inspection.

Forgive me for lack of correct terminology. 

For some reason i couldnt add pictures from the URL, so here is a link to a shared album if you dont mind taking a look.

https://photos.app.goo.gl/DsPoFsDHrRjebB7t5 

[Quick]

@ifbinary  I was looking at the picture you provided of the motor and idler. I'm not certain but something doesn't look quite right with the motor mount screws securing the motor mount to the floor? I see two holes that looks like it's possible where the original motor mount screws went? Did someone in the past drill holes and mount the plate to the base using other than the original mounting screws? I'm not sure about that but it caught my attention. Do some more manipulating of the idler and spring. Use your ears. A good trick locating noises at times is using a long screw driver or extension as a stethoscope...  

Edited March 31, 2020 by Quick
Spelling

[ifbinary]

I see what you mean about the holes on the motor mount, just noticed them after you pointed it out, however this unit is all factory from purchasing it 17 years ago and has never been opened up until yesterday (thought it was ten years old but was vastly off lol) .

I've added a couple more photo's to that album I shared. I took another listen and the noise is definitely coming from the area I circled, which I assume would point to the rear bearing? I unfortunately dont have a 240 outlet in my garage where i worked on it yesterday and my laundry room is pretty narrow so Its a tad difficult getting decent pictures, and access for listening/troubleshooting behind it while it has power.

[Quick]

6 minutes ago, ifbinary said:

I took another listen and the noise is definitely coming from the area I circled, which I assume would point to the rear bearing?

 

8 hours ago, 16345Ed said:

I’d check rear bearing...

 

[ifbinary]

i've ordered the rear bearing kit, will swap it out and respond back how it goes.

thank you all for your help

[16345Ed]

It’s a ball and socket joint. I’ve seen the ball part completely sheared off before. 

[ifbinary]

So I received and installed the rear bearing kit today and the issue persists.

Anymore thoughts on how I should proceed?

 

[ifbinary]

this was the kits I used

https://www.appliancepartscanada.com/products/5303281153-120?_pos=1&_sid=2d22867a8&_ss=r

[Quick]

@ifbinary Usually in a case like this the tech is familiar with machine and will inspect things while he's got it apart. Loose screws, front seals and or front supports making sure nothing is stuck in there that don't belong there. Best I can tell you is listen back in on that idler area seeing you got it back together. Someone mention a crack in the blower wheel. I've not seen that but it wouldn't surprise me. That's a tough one buddy. I'd like to come have a look. But like a good neighbor. Stay over there. 

[Vance R]

One idea would be to run dryer with the heat off. Air fluff or cool down to see if it is heat related.

[ifbinary]

On 4/4/2020 at 11:00 AM, Vance R said:

One idea would be to run dryer with the heat off. Air fluff or cool down to see if it is heat related.

tried that, same issue. i'm going to be taking another look at it tomorrow, borrowed a stethoscope and an extension cord so i can work on this in my garage where i dont have power. hopefully i can isolate where exactly this noise is coming from. 

[ECtoFix]

On 3/30/2020 at 7:43 AM, ifbinary said:

manually rotating the motor, there is some slight resistance and can hear what sounds likes brushes, unsure if this is a brushless motor or not?

I've only ever worked on just MY own dryer....and a friends.  BUT...I've worked on COMMERCIAL-grade equipment having motors of all sizes, types & loads for over forty years. 

Anyway.  I've been watching this thread for a week and now gotta post something.

Your previous statement of rotating the motor (with NO load, belts attached, etc.) with a sound like it has brushes...got my attention.  It's an induction motor.  No brushes.  No...ANYTHING.  There's NOTHING to drag the motor's rotation except the actual load of the belt & fan... and an internal centrifugal switch...which should be barely noticeable.

To FURTHER check the motor's bearings, GRAB the motor shaft like you would the horns of a bull (both ends, if possible).  Try wiggling it.  LONGITUDINALLY (length-wise of the motor's housing) AND LATERALLY (up & down and side to side).

If there is any... ANY play - either way...then one or both bearings are DONE.  SO, replace the motor.