I searched the web for info on information on repacking the front bearings on my 2000 Yukon xl, but ended up with zip so I'm throwing out what I found it may help someone...It started with my wife and a trip to Lubbock TX. After returning I noticed a rythmic grind~growl (pronounced rhum-rhum-rhum). I asked when it had started, and it started at the end of the return trip. I went through the gauntlet checking fluids, tire wear, drive shaft, u-joints ect. I pulled the front wheels and the passenger hub assembly sounded like gravel had invaded. Searching the web (the dealers had closed) I found nothing to to help me along. I started by disassembling the break caliber, rotor, unbolting the hub assembly and disconnecting the speed sensor. I looked over the hub assembly and found it to be un-serviceable (yes on an item the should require maintenance every thirty thousand miles) In big bold stamped letters it stated "Warning do not open" OK, So I wait until the next morning and call the GMC dealer~give him the part number and verify that yes it is an unservicable part. (he checked he had one $330.00) I call my local auto parts store, she has the part $154.00 with the recommendation to replace both at the same time. ok... parts went in fine evil rythmic hummmmm,hummmmm,hummmmm is gone and the suv is back on the road. Lets recap you can not repack the front bearings on a 2000 Yukon XL, The Dealer has the part for what you would pay for two at a local auto parts store. you will need a metric wrenches and sockets. if cost effective replace both the drivers and passengers at the same time.