I have greased my bearings twice in 8 years and they are cool to the touch every time I take it out. While I do not recommend my method, my point is that bearing maintenance annually is like changing your oil every 3k. If you run through salted roads and snow all the time or death valley all summer (extreme service) it might make sense. If you suspect problems it might make sense. If you run in the sunshine on decent roads (like me) it doesn't. Annual tear down and greasing is old thinking considering the improved synthetic grease available and a more realistic interval is bi-annually or longer. Adjust the brakes annually. Just one man's opinion.