Welcome to VE.
I have a BL-51 and so does another forum member davidsss in Australia.
I think it could be time to remove the headsheoll and cartridge to prevent damage while you work. Then, remove the belt and finally the platter to inspect and re-lubricate the motor which I hope can be saved. I'm not sure at this time if the noise is coming from the motor or spindle bearing.
To remove the platter, lift it up on the platter's edge and strike the spindle with a very small (150g) plastic-covered mallet (only one or twice) and the platter should come off.
Once you have done so, post again for more advice.
If the belt is removed and the motor switched on, you will hear if it is the motor or the spindle bearing which has a problem.
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