Thread: Strange noise in 2HP dust extractor motor

Hi everyone, haven't been on for a few years as woodworking hasn't been part of my life recently but I'm working my way back in to it.
I have a Toolex 2Hp dust extractor that ran quite well for a few years (as well as these units run anyway) but I recently started it up to test it and the motor is making a horrible sceeching noise. I have taken the front plate off and had a look, the rotor was covered in what looked like either surface rust or dried lubricant of some sort so I have cleaned all that off (the stator is nice and clean) but the rotor spins on the shaft and can move up and down between the front and read bearings. The shaft seems to be splined but the rotor still spins over the splines and it looks like there may be space for a small key in the rotor housing but not on the shaft.

Any ideas on what the issue might be? It seems the noise is coming from the rotor spinning on the shaft and when I turn the motor off, the shaft stops immediately but I can hear the rotor spinning in the housing. The fan used to take a while to slow down after turning off but now it seems to just stop dead while the rotor slows down.

Cheers