One of the first real automotive jobs I learned to do was to pack wheel bearings. I was exceptionally proud of my accomplishment, even though I had two or three years before I would even be able to drive. Since then, I've been somewhat obsessed with proper bearing care.
Many people ignore doing wheel bearing maintenance it. Now, if you're one of those people, maybe it's time to pay attention. Most mechanics recommend bearing maintenance every 12000 miles or once a year. Check your owner's manual for specific recommendations.
The axles on your pull behind travel trailer or fifth wheel, or the steering axle of your motorhome, all need it. The steering axle of your rear wheel drive car, the rear axle of a front wheel drive car, and even the axle on a tow dolly.... All of these bearings require care.
Here are the basics of packing wheel bearings on a trailer with drum brakes.
• Jack up the axle and safely support it.
• Remove the wheel and tire.
• Remove the dust cap.
• Remove the cotter pin.
• Back the retaining nut off and wiggle the hub assembly to loosen the outer bearing on the axle.
• Remove the retaining nut, washer, and outer bearing.
• Slide the hub assembly off the axle stub.
• Clean the brake shoes, backing plate, and axle stub so they are ready for reassembly.
• Knock the inner bearing and grease seal out of the hub.
• Clean the brake dust from the brake drum, and the grease and dirt from the hub.
• Clean ALL, I repeat, ALL the old grease out of the bearings.
Now you should be ready for packing and reassembly.
• Inspect the bearing races in the hub and put a light coating of grease on them.
• Hand pack grease into the bearings or pack using a bearing packing tool.
• Put the inner bearing into the hub. Install a new grease seal.
• Put a very thin coating of grease on the lip of the seal.
• Carefully slide the hub assembly on to the axle shaft, taking care not to damage the seal.
• Slide the outer bearing on to the axle stub, then the washer, and thread on the retaining nut.
• Tighten the retaining nut while rotating the drum taking all the slack out.
• Back the nut off and set the preload with a torque wrench.
• Install a new cotter pin.
• Replace the dust cap.
• Adjust the brakes.
• Repeat on the remaining wheels.
These are just basic instructions. For complete step-by-step procedures, with pictures, get a manual for your specific vehicle. Clymer and Chilton have manual for most popular vehicles and a chassis manual for your motor home is usually available from the dealer. Instructions for trailers are available from the axle manufacturer.
Packing wheel bearings is a dirty job. You might not do it yourself. But, knowing how to do it will help you appreciate what you are paying for on the line item "pack wheel bearing" on your work order at the shop.
Editor's note: My husband, Bob Nilles, wrote this article. He does most of the maintenance on all of our vehicles, including our motorhome, travel trailers, mini-vans, Suburban, utility trailers, and tow dolly. He also does most of the mechanical repairs on these vehicles, as well as on our tractor, mowers, and other implements with wheels and engines.
Go to the page listing the other articles Bob wrote for RV Life and Travel.
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