Why have my magnets come unglued? Perm 132 motor

[skyeg3]

Hello all, I have a perm 132 motor in a custom ATV build. We recently disassembled everything to paint the frame and we put everything back together and we went to turn the motor and it sounded like there were rocks in it! There were also some strange things happening with the electronics before we started it. For instance the potentiometer that adjusts the top speed/power of the motor was feeling kind of nasty and not smooth like it used to. Also there was a much louder clunk coming from the reversing contactor at one point. We are using an Alltrax controller (sr72300) Anyway - we disassembled the motor and found that six of the eight magnets that were supposed to be glued to the housing had come off and were just sloshing around with the rotor! We are completely confused because the motor was working fine before we disassembled everything two months ago. It's just been sitting on a workbench since then. Is there something that we could have done wrong with the electronics that would make the magnets come unglued? I was riding the vehicle around fast before disassembly but I don't think I was running it hard enough to get the motor hot. I ended up being stopped that session because of popped tires – not a lack of power or anything motor related.

Anyway, we are totally stumped. Help and clues appreciated.

 

[Balmorhea]

Were you driving the motor beyond its spec power?

 

[markz]

I was riding the vehicle around fast before disassembly but I don't think I was running it hard enough to get the motor hot.

Could be anything from running the motor to hot, to a QC issue with the motor build to having a junk motor from some unscrupulous manufacturers using inferior magnets and glue. If you buy from a reputable store, those problems are mitigated.

Look at the winding wires to see if it got too hot.

 

[skyeg3]

We are running the motor at 72 V and max 200A. According to most sources that is within the range of this motor however I have seen one German seller saying that it only goes to 60 V.

I am uploading a few pictures. My current plan is to try to remove the remaining two magnets then reglue all eight of them using lord 406/19 acrylic adhesive. Part of me wants to do this tomorrow morning so that I can have my vehicle for my trip this weekend. But also I don't use the wrong glue and if it would be better to get new magnets I also might want to do the right thing long-term and postpone the fun on this trip. Can anyone comment on whether this glue would be okay to use? And if I should search for new magnets?