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Dealing with Harman squeal - Pulling auger / motor

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by TheMightyMoe, Nov 8, 2012.

  1. TheMightyMoe

    TheMightyMoe Minister of Fire

    Joined:
    Aug 2, 2012
    Messages:
    543
    Loc:
    Fairbanks, Alaska.
    Disclaimer - I am stupid. So don't do anything I say, you've been warned.

    So after my Harman squeal problem and the 10 different ways to deal with it, I was told. I tried many, and decided I would make a little guide to help others deal with it. This is just my opinion, and the sounds we all experience maybe different. It seemed like a lot of people AVOIDED finding the problem, if possible. Many had to turn to dealers or were under warranty.

    Some things people said caused the problem.
    1. Rubbing metal parts / rubbing fines.
    2. Full fine box / Fines getting jammed into places.
    3. Built up creosote at end of Auger/Chute.
    4. Bad motor / parts.
    Some cures people said:
    1. Mix graphite powder into unit / spray graphite powder
    2. Scrape end of auger area
    3. Replace motor / auger / bearing
    4. Vacuum fine box / lubricate inside
    5. Lubricate motor shaft
    6. Run the unit on HIGH for a extended time
    7. Vacuum from bottom of hopper.
    8. Move auger blade around left / right / beat it (Don't do this...)
    Now every problem is different, not being a fan of graphite / lubricants. Graphite in many cases masks problems, you commonly see people put graphite in locking mechanisms as a “cure”. Having taken apart many locks, usually there is a problem, that the graphite is masking. Many time's the lock just needed a cleaning.

    Likewise, lubricant has it's places, but with sealed bearings, sealed greased motors, you shouldn't need lubricant. Also lubricant will attract dust/fines, so I'm going to avoid putting any in my fine box as long as possible.

    In my case the fine box was FULL, the bushings were coated in fines, and after cleaning, the squeal the did not go away. Also the end of the firebox end of auger was clean and free of build up.

    Here is my guide to addressing the squeal issue, by cleaning the stove thoroughly by removing the auger and motor.

    First things first. Do a overall cleaning of unit per manual. Empty and vacuum the fines box. Scrap the fire box, and around the auger chute. Run the unit, see if it helps. If not, let's go a little farther

    Pulling motor and auger.
    1. Unplug the unit.
    2. Remove the right, bottom, and back covers.
    3. You will see a motor connected to the auger with a fan on it.
    4. If you want to try and find the noise, plug the unit in, don't electrocute yourself, and run it in test. You should be able to tell if the noise is coming from the back or front.
    5. Unplug unit, to remove motor, unplug it from stove, via terminal connections. They should be color coded. You may have to remove some zip ties, so have some extra on hand.
    6. Now you can either remove the auger plate (Two 1/2” nuts), and pull the motor/auger all at once, or undo the cam block (One (7/16” nuts), and pull the motor first.
    Now that the auger and motor is removed, you should be able to clean the chute / auger extensively, and vacuum the fine box / rear of chute out more effectively. In my case, fines had filled the unit, and were getting built up all over the end of the Auger at the bushing. Also my cam block screw had come a little lose, which could have caused issues as well.

    Now with the motor separated from the Auger.

    Hold the auger in the empty chute, and give it some spins. There should be no rubbing of the auger and it should spin freely with no resistance.

    There are a couple of ways to test the motor. Plug it in to the stove, run it in test mode, and watch/listen. The motor should spin at a constant rate (Matching feeder light) and not slip.

    You can also manually turn the motor with your hand / wrench. Just be careful not to damage the shaft.

    Reassembly – Make sure cam block is on in right direction.

    1. There are 2 ways to do this, mount the auger on stove, then mount the motor on the auger.
    2. Assemble the auger and motor then mount it on the stove.
    While option 1 is the way I believe it was meant to be done. I believe option 2 is the better choice because you will be able to put a lot more torque on the cam bolt easily(Connects motor to auger), and lining it all up behind the stove is not the easiest thing (But doable)

    Some useful tools -
    Flat head screw driver
    7/16" 5/16" and 1/2" Sockets / Wrenchs
    Mirror (For viewing burn pot holes)
    Vacuum with hepa / fine debri filter
    2" inch wire brush for cleaning chute.

    Here is where you can either pull the bolt off the cam and remove motor, or just remove auger plate nuts, and pull it assembled.

    Motoraugerconnectedtostove.jpg

    Motor/Auger pulled. Only takes 3 nuts, and 2 terminal connections to pull it. I had a lot of fines stuck against the auger bushing, and that I removed. Remove the cam bolt to separate the two.

    Motorauger.jpg

    Now you can clean the fire box chute thoroughly, my vacuum hose is a 1" so I actually run it through. Also use a 2" grinding wheel to clean the chute. Other picture shows where auger sits, and the 2 bolt's that hold it in place.

    Clean chute Firebox.jpg Auger bolts..jpg

    Re-assemble. Make sure your CAM bolt is on tightly, and lined up with the straight shaft on the motor. Mine had come lose, which may have caused some of my squeal problems. Notice the rubbing on the shaft, the unit was still catching the auger and turning, I'm guessing when the pellets were just right, it caused shaft to slip.

    loose cam bolt rubbing.jpg

    This made in USA tool kit was really all I needed to work on this made in the USA piece of equipment. This kit has come in handy many many times.

    Some tool shots.jpg

    Good luck!

    Video of squeal - Max your volume for realism.

    Attached Files:

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  2. Delta-T

    Delta-T Minister of Fire

    Joined:
    Feb 27, 2008
    Messages:
    3,095
    Loc:
    NH
    your disclaimer is unwarranted...stupid does not allow you to make such a good description and detail of your process. Nice job....so long as it solved your squeeking problem.:). It can be tricky to get the 2 bolts that hold the "eye" plate for the auger bearing on perfectly aligned.
  3. TheMightyMoe

    TheMightyMoe Minister of Fire

    Joined:
    Aug 2, 2012
    Messages:
    543
    Loc:
    Fairbanks, Alaska.
    Meh, being stupid is the easiest disclaimer there is. WHYD YOU DO THAT? I told you I'm stupid... Thanks though =) It solved my problem, hoping it helps others too.

    Yeah, getting to those 2 bolts assembled isn't the easiest, but trying to line up all the shafts / cam block isn't fun either. If I wasn't so lazy, I'd of grabbed my 7/16 ratchet wrench, and the eye hole bolts would've been cake to tighten.
  4. stoaf88

    stoaf88 Member

    Joined:
    Oct 19, 2009
    Messages:
    235
    Loc:
    RI
    Great post

    This should be stickied
  5. XXV-AK

    XXV-AK Member

    Joined:
    Dec 1, 2010
    Messages:
    47
    Loc:
    ANC Alaska
    Excellent post and I will add this to my annual cleaning as well. So did it fix the squeal ? I have the same noise but not that long in duration. I scrap the throat and WD-40 the auger that keeps in quiet for about 7hrs. Thanks again.
  6. TheMightyMoe

    TheMightyMoe Minister of Fire

    Joined:
    Aug 2, 2012
    Messages:
    543
    Loc:
    Fairbanks, Alaska.
    I have been squeak free since.
    Eatonpcat likes this.
  7. XXV-AK

    XXV-AK Member

    Joined:
    Dec 1, 2010
    Messages:
    47
    Loc:
    ANC Alaska
    Good thanks again. I know what I'm doing tomorrow :)
  8. XXV-AK

    XXV-AK Member

    Joined:
    Dec 1, 2010
    Messages:
    47
    Loc:
    ANC Alaska
    One question I have is when pulling out motor and auger as one unit how far does it extend back? The reason I'm asking is my wall is 5 inches from the back cover. AK
  9. TheMightyMoe

    TheMightyMoe Minister of Fire

    Joined:
    Aug 2, 2012
    Messages:
    543
    Loc:
    Fairbanks, Alaska.
    I didn't measure =/ But the only length added will be the auger length, so maybe 8-11 inches (Guessing).

    Either way you can pull the 2 nuts, see if it'll pop out, I'm pretty sure you'll have room because there is also space inside between the motor and the back cover.

    Otherwise you just have to undo the cam bolt, just make sure it is on real good and in the right position when you put it back together.

    The fact that you WD-40 the auger shaft, and the squeal stops, makes me think the auger is hitting/grinding on something.
  10. Hellfire

    Hellfire Member

    Joined:
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    Loc:
    Sunbury , PA 17801
    From foreign and domestic parts?

    Assembled in the USA.
  11. TheMightyMoe

    TheMightyMoe Minister of Fire

    Joined:
    Aug 2, 2012
    Messages:
    543
    Loc:
    Fairbanks, Alaska.
    It's a shame isn't it =/ I got most my hand tools before they started the switch over.
  12. Hellfire

    Hellfire Member

    Joined:
    Oct 2, 2012
    Messages:
    153
    Loc:
    Sunbury , PA 17801
    I hear ya I see patent pendings do not apply to china just look at all the knock off tools flooding the market but what do, we all buy things with $$$ in mind and value.

    It comes down to 2 things : We either lower are labor rate like china (which = lower $ on the good/products) which is not gonna happen or lower the corp. tax (among other things)to make our stuff cheaper to compete domestically.

    Unfortunately we are stuck.


    But the best thing about us is we can adapt and think of ways to get us out of it i hope.

    Nice tutorial on your fix .
    BTW that`s one thing we have is the ingenuity to fix things.
    ;)
  13. dshatto1981

    dshatto1981 New Member

    Joined:
    Dec 24, 2012
    Messages:
    1
    This is probably a really stupid question, but does the hopper need to be competely empty before removing the auger? I have been dealing with this squeaking all night and it is driving me absolutely nuts!
  14. Lousyweather

    Lousyweather Guest

    yep.....when ya pull the slide plate, the hopper will empty.....onto the floor
  15. Jefflitzy

    Jefflitzy Member

    Joined:
    Jan 18, 2009
    Messages:
    58
    Loc:
    The other province of Ontario.
    Had the squeal on my P61 last night - It was the slide plate rubbing . Sprayed some Boeshield on the plate and has been quiet ever since.

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