Bench Grinder: Motor Gets Hot
A bench grinder will get quite warm, however, if it gets too hot, it may overheat. If your motor gets too hot while in use, check the following parts: the bearings, extension cord, motor, and grinding wheel. This is a common problem, and we have listed the most likely solutions below. This is a general guide. For more specific instructions relating to your model, please refer to your owner's manual.
Bearings
If your bearings on your bench grinder are worn out, it can cause the motor to get hot. To replace the bearings, first remove the screws to remove the hubs. Next, test the shaft to see if it is loose, and if so, remove it by pulling it out from one end. Remove bearings from either end of the shaft and hammer in the new one onto the shaft. Reassemble your grinder by placing the shaft back in the grinder and securing it by placing the hub back on.
Motors
If the motor is shorted out or there is a burnt stator in your bench grinder, it can cause the motor to get hot. Replace the motor to fix this problem.
Power Cords
If the extension cord is too long and it is also not the correct gauge, it can affect the motor getting hot and overheating. If you think that this might be responsible for causing your bench grinder’s motor to get hot, make sure you replace your extension cord with a new one that has the correct gauge. This should fix your problem.
Wheels
If you are pushing the object that is being grinded too hard against the grinding wheel in your bench grinder, then it can create friction and cause your motor to get hot. Doing so for long periods of time can cause damage to the grinding wheel, in which case you will need to replace the grinding wheel to fix this problem.