Wheel bearing O-ring, new knuckle seal, new dust seal.
1) Raise the front of the truck off the ground and support it safely either on a hoist or with a floor jack and proper jack stands. Don't use concrete blocks, pieces of old wood etc. Having the truck fall on you will ruin your day
2) Remove the front wheels.
3) Unplug the connector for the ABS sensor from behind the inner fender liner. Unclip it from the frame and from the brake hose.
4) Pry the caliper away from the caliper mount to compress the pistons in the caliper. Remove the bolts that hold the caliper mount to the steering knuckle and set the caliper and mount on top of the spring . Don't let the caliper hang by the hose. Also remove the vacuum hose that goes to the fitting on the knuckle if you have ESOF.
5) Remove the brake rotor . It may take some persuasion.
6) Remove the cotter pin and nut that attach the tie rod end to the knuckle.
Hit the side of the knuckle where the end goes through to pop the end out. If you use a pickle fork (tie rod separator) on this you may destroy the boot on the tie rod end.
7) Remove the outer hub by squeezing the retaining ring and then pulling the hub out. Sometimes it will take a bit of persuasion with a soft faced hammer to remove it.
8) Remove the snap ring and thrust washers from the axle.
9) Remove the bolt that holds the ABS sensor wiring to the knuckle.
10) Remove the 4 nuts that attach the wheel bearing/hub assembly to the knuckle and remove it. There are a few ways to remove the wheel bearing/hub assembly. You might try using a long punch and hitting the studs from behind (make sure you have new studs first), you might be able to pound a thin chisel in between the assembly and the knuckle to break it free, you might be able to use a 3 jaw puller pushing against the axle or you can reinstall the wheel and hit the back of the tire with a sledge hammer. It can be pretty hard to remove but it will come off.
11) Now that you've got the wheel bearing/hub assembly off you'll see the axle needle bearing or spindle bearing as it's sometimes called. If it is dry you will have to replace it and maybe the axle too if there is damage on it. If there is still grease in it you'll want to clean it out and regrease it.
12) Remove the thrust washer from the axle and note which direction it came off. The 4 grooves go to the back.
13) Remove the axle . I usually just pry it out with a pry bar on each side behind the housing dust seal. You can also tap it out from behind.
14) I find it easier to remove the knuckle seal with the axle still hanging in the knuckle. It comes off with a hammer and chisel or punch.
15) Now you can clean up the axle and closely check the U-joint to make sure it moves freely and doesn't bind or feel loose. Also examine the axle for any unusual wear etc.
16) While the knuckle is still attached I like to clean out the inside of it. If it's rust and dirty the new seals won't seal properly which can lead to bearing problems and also cause the ESOF to not work right. I use a ball hone on a drill to clean it out. You can use fine sandpaper if you don't have a hone. The main thing is to make sure the inside of the knuckle is clean and smooth.
17) Remove the lower and upper ball joint nuts. Some new ball joints come with nuts, some don't.
18) Using a pickle fork, knock the upper and lower ball joints out of the housing. Keeping one of the ball joint nuts on a few threads will keep the knuckle from falling off and landing on your toes
Now remove the knuckle.
19) Clean the end of the housing and inside the tube.
20) Now you're ready to remove the ball joints.
Start by removing the snap ring from the lower ball joint.
Remove the old ball joints either with a ball joint press or by pounding them out. First the lower and then the upper .
Clean the rust and junk from where the ball joints go into the knuckle. I steam clean the knuckle but it's not usually really necessary.
In our shop we have drivers to install the new ball joints but most people use a ball joint press so I won't show you that part. You should be able to get a ball joint press from a parts store or rental place. It should have instructions with it. Basically it is like a big C clamp with cups and spacers etc that will press the ball joints into the knuckle.
21) Install the knuckle onto the housing again and loosely install the nuts on the ball joints. Tighten the lower ball joint nut to 150 ft.lb. Tighten the upper ball joint nut to 70 lb.ft. and install a new cotter pin.
22) Next, install the new knuckle seal onto the axle. You'll need the special driver made for doing that or some people have made drivers out of PVC pipe. The seal has to bottom out on the axle.
23) Install a new dust seal on the axle. It usually just pushes on by hand but you may have to tap on it a bit.
24) Lube the outer sealing surface of the knuckle seal with good quailty wheel bearing grease or silicone dielectric grease and install the axle. The same tool that was used for installing the seal onto the axle gets used to install the axle into the steering knuckle. The axle can't go in too far so don't worry about the seal pushing out the back or anything. The driver pushes the axle in to the correct depth. Lightly grease the thrust washer and install in onto the axle with the 4 grooves to the back.
25) Clean and lube the needle bearing with good quality wheel bearing grease. The bearing needs to be packed with the grease. Force the grease in with your fingers until no more will go in. Replace the yellow O-ring on the wheel bearing/hub assembly. Make sure the 4 studs are in good shape and clean.
Install the wheel bearing/hub assembly into the knuckle and tighten the 4 nuts to 135 ft.lb.
26) Lightly grease the outer thrust washers and install in the order shown and then the snap ring to hold it all together. You may have to pry the axle out a bit to install the snap ring.
27) Replace the O-ring on the outer hub and install the hub.
28) Install the brake rotor . I use 1 nut to hold the rotor on and tight while I install the caliper.
29) Install the caliper and mount.
30) Hook up the ABS sensor connector, vacuum hose etc.
31) Reattach the tie rod end . Tighten the nut to 50 ft.lb. and install a new cotter pin.
Stolen from another site..