Hi, I'm Pete. Welcome to JustAnswer! I'm reviewing your question now, and will post back with your reply ASAP.
A treadmill motor can cause strange noises if it is clogged up with dust and other debris, however loose bearings are more likely to be the cause of a grinding noise.
To fix this, the bearings will need to be replaced.
Do you plan to attempt the repair yourself, or are you looking for a repairer in your area?
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