If you want to conduct auto repairs for your Yamaha XS 400 then it is usually a good plan to have a Workshop Manual to use as reference in case that you want to know the way to remove a specific component including Wheel Bearing and match it again successfully.
Yamaha XS 400 Workshop Manuals gives you precise diagnostic wisdom with regards to your car so if something is not working it helps you find out what the issue is and the best way to repair it. You will be able to determine if this can be achieved on your own or that the job is simply too big you can actually make a booking for your XS 400 in with a decent car garage.
Yamaha XS 400 manual