Are my bearings bad?
Your bearings may be bad if the wheel is making much more noise than normal. The sound can be described as a scratching, almost whistling noise. You may also experience a "pop" sound or ride feeling every time the wheel rotates around.
The bearings in your EUC may go bad with heavy wear and tear, especially if the wheel is subjected to heavy dirt/dust/water conditions. The much larger bearings used in the hollow motors(found in the T3, EX, EX.N, RS, and Monster Pro) are more prone to issues as there is a larger area for dust, water, and other debris to potentially penetrate the bearings' seals.
It is possible to replace them at home, but it's difficult. Most of the time we will send you a replacement motor, and you'll send us back the motor with defective bearings.
If you think your bearings are defective, send us a video of the wheel making a sound. and we'll be able to assist you further.