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noisy belt driven Air Handler

Hello to all.

 I recently changed a blower motor (1/3 hp) that uses a belt to drive the blower on an old 3 ton air handler that customer states had started to make squeeking type of noises before it died. I replaced the motor and belt and about three weeks later it was making a constant high pitch noise worse than before, not sure where its coming from. I adjusted the pully on the motor to be more in line with the pully of the blower and for the remainder of the time I was there it was fine but it started again soon after that. Now it starts with a constant cycle of humming and then squeeking and again humming then squeeking.

Other important things I noticed are

1)If I remember correctly when I removed the cover the noise stopped

2) The new belt after 3 weeks seemed to have been a lot looser then when first installed.

3)Noise only happens with belt in place

4) blower has pillow type bearings that seem to be properly greased.

Any help would be greatly appreciated, Michael


  • RJ_4
    RJ_4 Member Posts: 484

    Check the motor sheave ( you call it a pulley ),  is it ajustable, if so is it worn and grooved, this can cause noise.

    There was an error rendering this rich post.

  • Techman
    Techman Member Posts: 2,144
    edited September 2013

    Remove the belt, grab the(driven) sheave and shake it up/down/sideways/back/forth.Do the same for the motor. Do you feel any movement, hear any clunk ,clunk noise?  Is the pillow block bearing a one piece bearing or is it a babbit type( take apartable)? Grease or oil in the bearings? A belt that loosened up in a few weeks is not right, possibly it was over tight, wore out the bearing and streached the belt out a little?
  • charliechicago
    charliechicago Member Posts: 130

    its been a long time but thank you for the responses. I changed the pulley on the motor and they have not called back.
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