Mac motor making clunking noise and not spinning

I'm trying to trouble shoot a mac motor which previously had been working. There are very few miles on this motor. After working on a battery issue and testing the system, the motor started to make a loud clunking sound and not spinning. It jerks a bit and makes maybe an eighth turn each time. It sounds like a metal on metal impact inside the motor and causes the disc rotor to ring (it's a sharp impact).

I took both sides of the motor off, and everything spins smoothly, and nothing seemed out of place, but the problem remains when reassembled. The wheel freewheels fine too.

Any ideas?

I've done some searching and all the Mac motor problems I've found are clutch or Hall sensors. I suppose I could try replacing the clutch, but it freewheels fine and is practically new.

Sensor or sensorless?

Ykick said:

Sensor or sensorless?

Click to expand...

I'm running it sensorless to test it. It was working without Hall sensors before, it would simply cut out at a fairly low RPM. Using 40 amp Grifineon controller.

This really seems like a mechanical problem.

I dunno Macs, sorry. Worked with many Q motors, clutches can bang like hell but it’s fairly obvious looking at the clutch.

I’m saying poor or fouled sensor operation can sound pretty mechanical too.

I guess it's quite likely the clutch. I can hear the motor spinning, and each time there's a loud clunk, the wheel lurches a bit. Seems like it happens once per clutch revolution.

I've had that issue from wiring, shorting out/disconnected hall wire at connector and Phase wires entering the axle...1 in 5 times it has actually been mechanical yet the symptoms usually all sound mechanical. When it was mechanical, it was a growl, slip or intermittent low power.