" Put the hub back on the spindle and leave out the outer bearing. Screw the nut on the spindle. Then grab the hub and pull it toward you hard and fast , the nut will bottom against the bearing and the bearing and seal will come out together".
(Above, what Ken said)That is the way we did it on the fleet vehicles at work. Its fast but every once in while you did damage a seal doing it this way. You can use a seal puller if you do not want to risk damaging the seal. Stick the seal on the spindle and if feels like the rubber is doing its job I'd reuse it.
I remember we paid $1.67 for most front wheel bearing seals from our warehouse supplier. That was back around 1999. When I went to the parts store for my personal car it was $12.00 for a seal. No profit there.
I don't why but there is nothing I hate more than packing wheel bearings. We did them every 30,000 miles at work, we had 400 vehicles. So I've done thousands of them in the thirty-year's I was there. If you pack them correctly, every 30,000 miles, they will just about last forever. We never lost wheel bearings. If you do them wrong you can burn them up in a couple of day's.
First look at the bearings and races for pits. Any pits and they need to be replaced as a set. Sometimes they are a little discolored. I still used them and they never caused a problem. If they are blue I'd get rid of them. You can knock out the races with a punch and hammer. Wear goggles because the race is so hard pieces can chip off of it. You can install a new race with a punch but you might chip the edge of it. If you go slow and evenly you can do it without damaging it. Its better to find something the same diameter and drive the race in with that. Harber Freight has cheap set of seal and bearing race drivers. When driving it in, when the race bottoms out it will make a ringing noise to let you know its in all the way. Hit it in several places to make sure its evenly seated.
Next, wipe out all the old grease from inside the drum and off the spindle. If your unsure of the type of original grease you should use solvent to clean it all out of there and out of the bearings. Then spray the solvent off with brake clean so the solvent does not contaminate the new grease. One of the main causes of wheel bearing failures is combining two different types greases.
Coat the spindle with a thin layer of grease, especially where the seal rides on the spindle. Coat the inside of the hub cavity with grease but do not fill-up the cavity. That space helps dissipate the heat from the bearings. You just want a lite coating of grease to prevent corrosion. Otherwise it gets rust in there and your wheel bearing grease will look like mud. Every factory untouched wheel bearings I have opened up had just the minimum amount of grease in the cavity
You probably don't have a bearing packer. So put a blob of grease in the palm of your hand and drag the large end of the bearing across your palm forcing the grease into the bearing. Keep doing this until clean, new grease, comes out of all the openings between the rollers on the small side of the bearing. You want the inside of that bearing "packed" with grease. Smear a good thick coating of grease around the outside of the bearing, so you can't even see it because there is so much grease on it. Drop the inner bearing (rear) into the drum. Grease the lip of the seal so it does not run dry. Knock the seal in with a hammer and something flat. It should go in easy if you get it started straight. Slide the drum onto the spindle and pop in the outer bearing which is loaded with grease inside and out. Then wipe off the excess grease where the washer will seat up against the bearing. Wipe off any grease off the washer and nut. This is to make sure you have a tight fit between the bearing, washer and nut. If you left the grease on there it could eventually work its way out between the surfaces and you would end up with loose wheel bearings. Stick the washer on, with the tab in the slot. Stick the nut on and tighten it firmly with a crescent wrench but not gorilla tight. Tighten it while rotating the drum back and forth. This pushes the excess grease out of the bearings otherwise after you have driven it a few miles the bearings will be loose.
This is the important part. We want "zero" preload on those bearings. If they are tight they will overheat, turn blue and start to pit and flake apart. After you have snugged up the nut with the crescent wrench back it off. Using your greasy fingers (so you cannot overtighten the nut) tighten the nut until your fingers slip on it. Now grab the drum, push and pull it in and out (towards you and away from you). Do not move it side to side. The correct way is to move it in and out (lateral movement).There should be no play. Back off the nut just a hair until you feel the slightest amount of movement. Then tighten it just enough to get rid of that movement but no more. Stick your cage washer on and your cotter pin. If the holes do not lineup you can back it off until it lines up. If there is just a tiny bit of play I'd leave it there. If its too much I would go the other direction and go to the next hole you can line up. You will find that after you have driven it awhile the bearings will always loosen up a little. Sometimes you need to go back and move the nut one hole. I rather do that than set them too tight.
All wheel bearings are done this way, even on large trucks, you do not overtighten them. On the Early Mustangs the shop manual had you tighten the nut to a specified torque and then back off the nut two cotter pin holes. I've tried this and it has no play in it when your done. You have no way of knowing how tight it is. I'm thinking Ford knew it would loosen up a little as the grease got forced out between the surfaces. GM had you tighten the nut and then back it off until you had just a few thousands of play.
Stick your new cotter pin. Not a nail like I've seen on some of them??? You can either bend the top of it backwards and over the end of the spindle and then cut the bottom one so it sticks past the hole but not so far that it rubs on the wheel bearing cap. You can also bend both of them to the sides. It seems to be what ever the mechanic prefers. I always bent them like the first way. It made it easier to pull the cotter pin out the next time.
Use a large socket to carefully tap on the grease cap so you don't smash it with a hammer! If you dent it could rub on the cotter pin.
Last, "torque your wheels evenly" with a torque wrench so you do not warp the brake drums. Most people overtighten them by hand with a big breaker bar because they are afraid the wheel is going to falloff. Then the next time they go to take the wheel off the lug nuts break off.
Here are some photos of a seal removing tool and a bearing race/seal installer set. Those race drivers make the job really easy. If you buy a set make sure there is one in there that will fit the race your trying to install. You can always grind one down if you need to. Or you can save $40.00 and just beat the crap out of the race with a punch.
