RV and tow vehicle wheels and hubs need regular inspection and servicing to ensure proper operation and long life. The schedule in your vehicle owner's manual is the best guideline for when to perform maintenance. Lug bolts or nuts ideally should be checked before each trip and torqued to factory specifications. Wheel bearings should be repacked with grease once a year or every 10,000 to 12,000 miles, whichever comes first. Failure to keep your wheel bearings properly greased is a pretty sure formula for having them fail out on the highway or off road. You can be sure that when they do fail it will be at just about the worst possible time and place! Wheel bearings on fixed drive axles, like on rear wheel drive vehicles, are usually lubricated by oil from the differential, so keep the differential topped off. Front wheel bearings and wheel bearings on any steerable wheels are lubricated by grease pressed into the bearings and should be regularly checked and re-packed.
Ideally lug bolts should be checked using a torque wrench to be sure they are adequately tightened to factory specifications given in the owner's manual. Since many driver's don't even have a torque wrench in the tool box at home, let alone on the road, the next best thing is to tighten the lugs with a proper lug wrench as tight as you can get them using your hands and arms. Do not use any kind of extender to multiply the force! Doing so can over-stress, stretch, strip, and even break lug bolts.
Wheel bearings on rear wheel drive axles are usually lubricated by oil from the differential. Keeping the differential filled to the specified level is essential for lubricating the bearings as well as protecting the gears in the differential. The bearings on the front wheels of rear wheel drive cars and the rear bearings on front wheel drive car use grease for lubrication. As indicated above, these wheel bearings should be repacked with grease once a year or every 10,000 to 12,000 miles, whichever comes first. You can have a mechanic do it for $100-200 but if you have the right tools and same basic do-it-yourself mechanic skills you can probably do it yourself.
How to repack wheel bearings. If you choose to repack the wheel bearings yourself I am sure you can find some good Youtube videos to guide you. But here are some basic instructions to get you started. First, here are the tools and supplies you will need: a jack, chocks for the wheels, a pair of Channel-lock style pliers, a pair of diagonal pliers, a long punch, a ball-peen hammer, a new cotter pin of the right size, and a can of waterproof grease. Once you have assembled your tools and supplies, put the vehicle in park, chock the wheel(s) on one side of the vehicle, release the parking brake, then jack up the wheel on the other side. Remove any decorative hub caps. Then remove the lug nuts or lug bolts and remove the wheel and tire. I use the back side of my pliers to tap the dust cap off the center of the hub. Then remove the cotter pin from the large castle nut on the end of the axle. To do this straighten the flat ends and pull it out using the loop on the other end. Diagonal plies are a good way to get a grip on the cotter pin to pull it out. It is recommend that you always replace the cotter pin with a new one when you put things back together. Remove the castle nut using Channel-lock style pliers and the washer/spacer behind it. The washer has a tab on it that slides in a slot on the axle. I put the nut and the washer inside the dust cap to help keep them clean and keep track of them. Grab the hub and alternately pull on each side so as to wobble it back and forth. This will cause the outer wheel bearing to pop out so you can remove it. Then pull the hub off the axle. To repack the inner wheel bearing you will have to remove it from the hub. Lay the hub down with the outside up, the use a punch and hammer to tap out the inner wheel bearing. Once you have both bearings out, clean them thoroughly with solvent and then let them dry thoroughly. You can buy a tool to press grease into the wheel bearings but, as I was taught by my father, who was a professional mechanic, you can do it by hand. Put a big glob of grease in your off-hand (left hand if you are right handed). Then pick up a clean bearing with your dominant hand and hold it with the biggest side down. Holding one side of the bearing press the other side down into the glob of grease repeatedly until grease pushes up between the rollers of the bearing. Then rotate the bearing to a new spot and repeat until you have grease pushing up between ALL of the rollers. Once you have pack both bearings you are ready to reassemble the hub. Lay the hub down with the outside down. Place the inner bearing into the back side of the hub (which is now on top). The bearing goes with the tapered end toward the inside of the hub and the wider side out. Then put the retainer on the hub over the bearing and gently tap it into place, making sure it is all the way in all the way around. Clean the axle and slide the hub into place. Then insert the outer wheel bearing into the hub. Once again the tapered end goes in first. Next comes the washer. Be sure the tab on the inside fits into the slot on the axle. Then install the castle nut. Tighten it using the Channel-lock style pliers until it is firmly in place, then back it out about a half a turn to release excess pressure on the bearing. You don't want that nut to be too tight or too loose! Align on of the slots in the castle nut with the hole in the axle and install the cotter pin. Bend the flat ends back toward the axle to keep the cotter pin from coming out. Then tape the dust cap back on and reinstall the wheel. Then you are ready to do the next wheel.
When you have the hub apart, inspect the hub and the bearings and replace any worn or damaged parts. Most of the wear will usually show up on the bearings, but loose lug bolts/nuts can allow a wheel to damage the hub and the lug bolts. Damaged lug bolts can be pressed or hammered out and replaced. A damaged hub should be replaced. I once encountered a badly damaged hub on a 50 year or trailer for which there were no modern replacements. I was able to have a competent welder repair the hub and I replace all the lug bolts for near factory perfect repair.
It is a good time to inspect the brakes and make any needed repairs while you have the hub off. The main things to look for are thin brake shoes or pads or damaged brake drums or rotors. Think brake shoes or pads should be pretty obvious. New ones have 1/4-3/8" of lining on the shoes or pads. If there is less than 1/8" of lining you should definitely replace then while you have things apart. Check the brake drums for ridges or a deep lip. Check rotors for ridges, warping, or discoloration that is a sign of over heating. Badly worn drums or rotor might be able to be turned at a machine shop to restore the braking surface. If there isn't enough material left in the drum or rotor for it to be turned it will have to be replaced. Inspect all the brake hardware and replace anything that is damaged, including weakened springs.
Regular maintenance of wheels and hubs will avoid premature wear that can result in extensive and expensive repairs.
Keep rolling, rolling, rolling!
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