Jump to content

Fix grinding sound from motor - loose magnets

Recommended Posts

Just took another motor apart this morning that has several issues, I'll post step by step instructions on how I go about repairing it.

  1. Remove the motor from the housing (scroll down to see assembly process and reverse the order), next remove shear key from the slot in the axle.
     click to enlarge image
  2. Remove the half clip
    click to enlarge
  3.  Remove the 3 screws, they are tight so take care not to strip them out.
  4. Slide the gear off
    click to enlarge
  5. Use c-clip pliers to remove retainer
    click to enlarge image
  6. Place motor on a hard surface and push down on rotor housing to overcome the magnetic field.
  7. It should slide down and off the shaft, note, you really have to push hard to do this.
    7.thumb.jpg.8f3725d893286e30326f7e878cd95b42.jpg - Careful not to lose the thrust washer7-1.thumb.jpg.710d6991bd7ba8a0e9546425b8a363a6.jpg

  8. push on the magnets, if one slides down you know they are loose, or if it makes that grinding sound just assume they are loose. Number each magnet so you put them back in the proper order

  9. With a screwdriver you can pry up the magnet to remove them

  10. Safe spot to store them is on the outside of the housing, be very careful handling the magnets, they are strong and if they slip out of your hand and snap against each other or a metal object, can easily break

  11. Once they all removed, clean all debris and old glue from housing and magnets. I usually give each magnet a good cleaning just before gluing it down.
    click to enlarge

  12.  this one had several issues, the other being a cold solder joint on one of the halls sensors. Note the 3 in the center of the picture, the middle one is loose causing erratic running of the motor.

  13. Starting the re-gluing of the magnets (using epoxy: buy on Amazon)

  14. All done, note magnets are flush to the outer edge of the housing. Now to wait 24 hours for the epoxy to cure

re-soldering all the halls sensor connections  14-1.thumb.jpg.8dca4726b581092dd7ece2fdc1502737.jpg Done, there were two cold joints, that means they weren't making proper connection. 14-2.thumb.jpg.0273bf405c8c725f26107c3fca496a1e.jpg 
Just showing how fast the stator snaps into place
Install snap ring

  install gear and half clip

  slide assembly back in housing

  Once fitted give it a spin to insure all is well. There should be a spacer and thin washer on the shaft.

  install cover and 6 allen screws, Note this is a spare motor housing, the reason it isn't laced into a wheel.




  • Like 2
  • Thanks 1

Share this post

Link to post
Share on other sites

I have another topic like this - 

These look like Neodymium magnets? No?

Mine are completely rotted ferrite ones.

Thank you for the instructions...


Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use and Privacy Policy.