Now to be honest, I don’t think I needed to replace my wheel bearings. They could probably have just been cleaned and regreased, but the cost was around $70 for both front bearings and the grease seals, and since I was already doing a brake job and replacing the auto locking hubs, it wasn’t much more work. Also, my Trooper is from 1991 and I think the bearings were never repacked since the factory. The service manual says they need it every 30,000 miles, and I was about 180,000 miles overdue!
There are several tools that do this for you. I am cheap though and just take a bunch of grease in the palm of my hand and work it into the open edge of the bearing until it squeezes through to the other side and then I make sure it’s coating the whole thing.
Here’s a short video demonstration how you can do it and keep the bearing clean until you are ready to install it:
Installing the Bearings
Adjusting the Preload
The procedure for setting the preload requires a way to tighten the hub nut and although you can do it by feel (I think many people do), the manual says to use a torque wrench. The cheapest way is buy a Ford 4-prong socket and grind off two of the prongs and grind down the other two to fit in the hub nut holes. It cost about $15 for the tool.
Now just reinstall the inner cam, the hub, reinstall the snap ring, reinstall the housing assembly, tighten the hub to rotor bolts, reinstall the brakes, put the wheel back on, lower the vehicle, and tighten the lug nuts.