1. The first step to rebuilding your bearings is getting the hubs off your truck. Our front axle was already disassembled when we got it, but yours might not be. Throw the truck up on jackstands. Grab the top and bottom of the tire to see if you can get some in and out movement. If so, it's probably time for a rebuild or repack. Also, if you get a squealing noise while driving it might be your bearings slowly dying. To do a quick check after normal driving, touch the hub. If it's too hot to touch, then it's time for fresh grease and maybe more. And finally, if mud and water crossings are your thing, then definitely repack your bearings regularly, and you might want to step up to some quality waterproof marine-grade bearing grease.