My range hood has a motor with an impeller on it. The impeller is attached to the rotor shaft by a nut that threads onto the impeller's... bushing I guess it's called, which is slotted, so that as the nut is tightened around it, the bushing is pressed into the shaft from all sides to prevent the impeller from freely slipping on the shaft.

The problem is, I guess the nut isn't pressing enough, and the impeller is in fact slipping on the shaft. I can tell because the bolt heats up so much from the friction that you can't even touch it. It also produces noise which is similar to the noise it makes when the nut is put on very loosely and there is a lot of visible slippage (I checked just to be sure).

I tried tightening the bolt, but so far was unable to tighten it enough to solve the problem. It loosens enough to allow slippage within minutes of first use. Is there any other way to increase friction? I was thinking maybe some kind of tape, but not sure which one would be effective and would be thin enough to fit. Or maybe just glue? Although I will eventually need to take the impellers off for cleaning.

For the record, the motor actually carries two impellers on the same shaft as shown on the diagram. The model is Kitchenaid KICU265HSS1.



  • 1
    Can you remove the nut and add a thin washer?
    – JACK
    Jan 26, 2020 at 23:05
  • @JACK I guess... do you mean to add friction between the nut and the black plastic of the impeller that way, to prevent the nut from slowly coming loose?
    – Nikita
    Jan 26, 2020 at 23:25
  • That's kind of what I was referring to. Then you'd be able to tighten the nut and prevent the impeller from spinning on the shaft.
    – JACK
    Jan 26, 2020 at 23:30
  • @JACK I will try that, thanks.
    – Nikita
    Jan 26, 2020 at 23:45

1 Answer 1


Put a drop of super glue on the bare shaft, then slide the impeller fully into place. Put the nut on without gluing it. Leave it for an hour so the glue can set up. You could also use a threadlocker liquid on the shaft. I have repaired loose impellers for combustion air fans inhigh efficiency furnaces. I also use this repair for bath fans and rangehoods.

  • Thanks! I applied blue threadlocker like you said last night, here's the result: a) I confirmed that there is no slippage now by marking the shaft and bolt with sharpie, b) The shaft still gets very hot, not sure if that's normal, c) I'm still getting a high pitched whining noise sometimes but not always. There is also an intermittent high frequency medium-pitch vibration / rattling noise which I identified to be caused by the flap (damper) vibrating / fluttering (one of its springs got dislodged).
    – Nikita
    Feb 1, 2020 at 0:36

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