Which condition requires the addition of shims on a motor mount?

The condition that requires the addition of shims on a motor mount is a soft foot condition. A soft foot occurs when one or more of the motor's mounting feet do not make even contact with the base, leading to improper support for the motor. This can result in stress on the motor frame, misalignment, and ultimately can cause premature wear or failure of the motor and connected components.

Adding shims helps to level the motor mount by providing support where there is uneven contact. This ensures that all feet of the motor are firmly against the base, which aids in maintaining proper alignment and reduces vibration, thereby extending the lifespan of the equipment.

Other conditions like overheating of the motor, poor alignment issues, and wear and tear on bearings do not directly require shimming as a primary solution. Each of these issues would need to be addressed through different methods, such as improving cooling for overheating, correcting alignment directly for alignment issues, and replacing bearings for wear and tear concerns.