Driving with a trailer increases your risk factors, due in part to the reduced braking and cornering of your vehicle. One way to mitigate this risk is to always ensure your trailer is operating in proper mechanical order. A regular requirement for maintaining your trailer is to inspect and lubricate the wheel bearings. The bearings wear with normal use, particularly if they are not lubricated correctly. Dirt and moisture can also cause wheel bearing problems. A bearing that has not been maintained can fail while on the road, leaving you stranded. Regular maintenance of trailers is a must. Greasing trailer bearings is one task that you should include in your routine maintenance. A basic rule of thumb for how often to grease your trailer bearings is once per season. Some simple steps will help you grease your trailer bearings in no time.
1. Raise one side of the trailer with a jack and support it on jack stands. Remove the center dust cap from the hub by grasping it with a pair of pliers and working it outward or prying it out with a screwdriver. Remove the cotter pin from the axle nut. Loosen the nut and remove it and the washer behind it. Some trailers have an additional guard placed over the axle nut that you will need to remove first.
2. Rock the wheel from side to side to loosen the outer bearing and cause it to slide outward. Remove the bearing and place it on a clean rag to keep dirt from contaminating it. Pull the wheel outward and straight off the axle. Place the wheel on the ground with the outside facing up. Reach in through the center opening of the wheel with a screwdriver blade and place it against the inside edge of the grease seal. Gently tap the screwdriver with a hammer until the seal pops out. Turn the wheel over and remove the inner wheel bearing.
3. Wipe as much grease as possible from the bearings with a paper towel. Use brake cleaner or shop solvent spray to thoroughly clean all of the old grease from the bearings. Inspect the rollers for pits or scarring, and replace the bearings and races if there are any problems. Wipe the grease out from the inside of the hub and spray the bearing races with solvent. Again, if you notice any pitting or scoring, replace the races and bearings. Clean the axle surface where the bearings and seals ride on it.
4. Place some grease in the palm of your hand. Hold the bearing in the other hand and work the grease into the bearing from all surfaces, turning the bearing as you go. Continue forcing grease into the bearing until you cannot push any more in. Set the wheel on the ground with the outside down. Place the inner bearing inside of the hub against the bearing race. Position a new grease seal onto the hub and tap it into the hub flush with the surface with a block of wood. The rubber surface of the seal should face inside toward the hub.
5. Apply some grease on the axle where the seal rides. Set the wheel and hub on the axle. Lift gently on the wheel and push the outer bearing into position. Place the washer on the axle and thread the nut on. Spin the wheel while tightening the axle nut finger-tight then back it off 1/16 of a turn. Place the cotter pin through the axle nut and bend the ends around it so it can’t come out. Replace the dust cap. Raise the trailer with the jack, remove the jack stands then lower it to the ground. Perform the same procedure for any remaining wheels on the trailer.