Bearings are components that will wear over time. It is recommended you use a marine grade grease when replacing.
Instructions for replacing your bearings can be found at: https://www.exp-one.com/resources/proper-care-maintenance/maintaining-the-bearings-on-your-expedition-one-tire-carrier/
Tire Carrier Maintenance instructions may be found at: https://www.exp-one.com/resources/proper-care-maintenance/proper-care-and-maintenance-of-your-tire-carrier-system/