This is how I service my '02 4WD
This is gonna be long, so be prepared. The worst thing about servicing the bearings is getting them removed. The reward of servicing them is that you get to pick and choose the time and place, and that it is easy to assess their condition instead of having to wait for it to break down and try to guess if it is the bearings or something else like U-joints. This will also greatly extend the service life of the bearing. My ‘’bearing mentor’’has 200 K on a set and counting. . Also once it is done the first time, anti- seize makes it easy the next time. I will run down a list of tools it takes first,how to make a puller accessory second,and finally a rundown on remove and install.
TOOLS: 3/8 drive socket [offset head is nicer to use]. 3/8 drive Torx sockets. Metric hex sockets. 3/8 drive TWELVE POINT metric sockets. Harbor freight 8’’ 3 jaw puller at about 15 dollars. [replace jaw nuts and bolts with grade 5 to avoid breaking ] You will use this puller to get off the outside half of the bearing and you will use a tool you make out of a piece of thick steel to take off the rear half of the bearing / hub assembly . I got an eight inch diameter ½ inch thick round cutout from a company that fabricates stuff for gravel pits If the steel plate you get is not round, it will be OK . Now visualize a pair of dice. Your drilling pattern will look like the five the four outside holes are 3 7/8 ‘’apart and are drilled to 5/8 diameter. The center hole of the five is drilled at one and a quarter inches . I used a quality hole saw and a drill press. Go slow and use cutting oil. Drill halfway through and finish from the other side. [chips clear easier] Some guys can drill steel plate without a drill press, but I cannot.
To proceed, jack up one side of the truck,jack stand for safety. Have truck in gear with 4x4 engaged. Remove wheel. On 3500 trucks, remove 8 nuts behind wheel and remove wheel spacer. When you remove the spindle nut, please note how tight this thing torques off and on. Value for the spindle nut is 175 ft lbs. Mine has a castle nut and I put a paint mark on it so I could return it to it’s exact spot –no torque wrench required. Next you must compress the brake shoe away from the caliper. It is always best to break loose the bleeder then compress the shoe away from the caliper. Tighten bleeder right away after spreading shoe and no air should enter brake lines. Next remove the two12 point metric sockets that hold the caliper on [from the rear]. Use 12 point socket ONLY. Remove caliper and place on milk crate- never allow caliper to hang by the brake lines. On 2001 and 2002 trucks, the caliper should remove easily. On earlier trucks the caliper and hub are in one piece and a different procedure is required. Do a search of Casey Veldcamp and hub puller and you will see what I mean. Other good stuff about hub pulling there as well.
Now you are ready to pull off HALF of the bearing assembly . Take the harbor freight 8’’ 3 jaw puller and tighten it. This operation will separate the outer hub from the splined shaft. I like to place an old chair cushion under the hub to catch it from falling. It may be helpful to tap the puller bolt with a hammer as you tighten it—it usually breaks free when you tap on it. . Set the first half of the hub aside. IF it is absolutely necessary to re-assemble the unit before proceeding further, you could use the axle nut to bring it back together. The danger is that you would not be able to see if the two halves of the hub were set at full depth. I avoided this by having the puller accessory tool ready to go BEFORE splitting the first half of the bearing assembly. . WHEW – too wordy I know. .
Now for the hard part. The last piece of the hub is held on from the rear with four metric bolts . Same as before 12 point sockets ONLY. Remove the bolts. four metric bolts that you took from Now place the puller accessory tool over the splined driveshaft. Use the the rear and thread them in from the front. Better yet, get four 14mm x 80mm fine thread bolts and use them instead—these longer bolts will thread in further and not risk stripping out. I was able to get grade 8 bolts at a local hardware store Tighten the bolts evenly and the hub will ‘’push’’ the shaft in. This baby is really tight and will be rusted on. As you get tighter, the pulling action can be aided by tapping the bolts with a hammer. The biggest advantage to this home made plate is that it keeps the drive shaft centered and involves no ‘’heat and beat’’ of the metric bolts from the rear. If the puller accessory you made is made from a round plate ,you can add the 3 jaw puller as before , and you will have 5 bolts pressing at once. . Other TDR guys have removed the rear half of the bearing assembly by loosening the 4 metric bolts and using the steering system of the truck to break it loose. They somehow place a socket between the metric bolt and the steering yoke and turn the steering wheel to press it off. Remember your brakes are off the truck before you try this!
Once removed, press out the bearing from the hub . Mine came out easily by just placing it over a standard aerosol [spray]paint can and tapping on it Examine the bearing,race, and clean it up. Some guys leave it in place and grease it with a needle, but mine was easy to remove. Use a high temp synthetic grease and work the grease into the bearing race on both bearings. By the way the replacement cost for one bearing assembly is $ 350 U. S. !
To reassemble, you must join the hub back together A press is ideal. Join the parts ‘’flush’’. If no press is available you can use a light hammer to get started and a six pound sledge to finish. Place the studded side down and place a 2x6 against the back side when pounding it in It sounds worse than it is. Of course ,use never seize on all rusted surfaces. When you put in the four metric bolts from the rear, use green locktite. Some guys disagree with me on this and use anti-seize instead. My first service was 16 months after delivery, and I am just stating that I found green loctite on the four metric bolts.
By doing this maintenance annually, you should be able to prevent a huge repair bill later . As difficult as this is to get apart now, imagine adding more time and rust! I personally witnessed a 5 year old truck that ruined every component on the front end—over 3 thousand to repair. It ‘’let loose’’ with almost no warning and nearly caused an accident. Please let me know how everything works out and feel free to ask questions. Figure 3 hours for the first side and less than two for the second.
EDIT: There has been discussion on TDR of whether or not the hub should be removed in two stages as described above. The other method involves use of a 50pound slide hammer that threads to the wheel studs My method at least gives a controlled pull and keeps the front driveshaft centered during the pull. The bearings are enclosed in plastic , so mabe some people think they will fall apart when pulled as two assemblies
Attention: TDR Forum Junkies 
