Dirty Jobs: How to Pack a Wheel Bearing
Bearings are integral components that keep your wheels turning and prevent friction from wreaking havoc on your vehicle. Properly greased bearings dissipate heat, alleviate the friction and weight on your wheels, and enable smooth motion over thousands of miles.
But that grease eventually breaks down or dries up — and does so faster in dry or dirty conditions — so it’s necessary to repack your bearings every so often. Warning: It’s a dirty job, but if you know how to pack a wheel bearing, you’ll save yourself from bigger issues (like the wheels falling off) in the future.
Getting Your Bearings
There are two bearings, inner and outer. Depending on whether you’re dealing with disc or drum brakes, the components you need to remove to access them differ. Start with lifting the vehicle, safely supporting it on jack stands and removing the wheels. Next, use a chisel and hammer to pry off the dust cap. Inside, you’ll find a castle nut, held in place by a cotter pin. Remove those and the washer behind them, putting all components to the side in the order they came off. Then, the hub should be free.
If there are calipers on your rotor, then you’ll have to detach them without disconnecting the brake lines. Then, place them to the side, secured to the chassis — never hanging by their lines. If you have drum brakes, remove the drum. Then, pull off the hub.
The front bearing should slide right out. Before removing the old grease, take a moment to check for metallic flecks, which indicate bearing damage and warrant a replacement. The inner bearing is held in place by a seal at the back of the hub. Use a hammer and flathead to pry the seal out, and make sure to have a replacement seal on hand.
To clean the bearings, use a wipe and brake cleaner, or soak them in kerosene overnight. Once they’re clean and completely dry (do NOT spin them with compressed air), inspect the bearings for signs of overheating (a bluish tint), scarring, pitting or other damage. If the bearings are bad, you’ll need to replace them with their races.
Pack It Up, Pack It In
Grab a pair of disposable gloves and squirt a palm-full of manufacturer-recommended bearing grease into one hand. Grab a bearing and press it into the grease, working your way around the larger end until you see grease forced through to the smaller end. Then rub the grease around the bearings until every nook and cranny is coated.
Alternatively, you can grab a bearing packer tool and let it do all the dirty work. Always keep new grease free of even the smallest debris. Replace the inner bearing back in the hub where it came out, and evenly press the new seal into place with the flat side facing out. Using a pipe or socket of a similar diameter, tap lightly to avoid any bending until the seal is either flush or just inside the hub.
Coat the spindle in grease and reinstall the hub. Then replace the outer bearing, washer, nut (torqued to spec), cotter pin and grease cap in the order you removed them. Wipe off any excess grease, so it won’t fly off and ruin your brakes. Put your calipers (if applicable), wheels and lugs back on, and you’re done! Easy!
Learning how to pack a wheel bearing is simple enough … but it is dirty, so be ready.
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Photos courtesy of Blair Lampe.