As routine maintenance and basic automotive servicing tasks go, packing wheel bearings isn’t one of the glamorous ones. It’s a messy job—and one that could cause serious damage or problems if not performed correctly. Not surprisingly, many enthusiasts put off this project as long as possible or avoid it altogether.
But properly greased wheel bearings are essential for safe driving, especially if a vehicle has modifications or is intended for even occasional trips to the dragstrip or road course. The wheel bearing, of course, is that cage of rollers that allows the wheel hub to rotate freely on the axle’s spindle. Grease lubricates the bearings to keep them cooler and reduce rotational friction. It also acts as a cushion between the bearing rollers and hub race.
Over time, the grease deteriorates, especially in wet and dirty driving conditions. If left unattended with inadequate grease, the bearings will eventually overheat and possibly cause expensive damage to the hub and/or spindle. In extreme cases, the hub/wheel could lock or even separate from the axle. That’s no fun when you’re cruising down the highway.
So, if you haven’t repacked or replaced your wheel bearings since Atari was the hottest thing in home video games, you’ll want to plan to get dirty and get the job done. It’s also a great idea to do it if you’re upgrading your brakes with, say, a disc brake conversion or a swap to larger rotors and calipers. And don’t worry if you’ve never done the job before. We’ve outlined the basics in the accompanying photos and no special tools are required.
The messy part of the job comes from mashing grease into the bearing assembly via a dollop of grease in the palm of your hand. Make sure you’ve got disposal gloves before getting started, otherwise your spouse likely won’t let you back in the house after the job is completed.
Get to it!
01. The project starts with the removal of the wheel and tire. We are using a lift for this story, but it isn’t required for the job. The car only needs to be raised far enough for the wheel to be removed.
02. Next, the brake caliper is unbolted and removed from the disc rotor.
03. If care is taken during removal, the caliper can be set aside without having to disconnect the brake line, which would require a time-consuming rebleeding procedure. If there is no place to safely lay the caliper, it can be hung from the chassis with nylon tie wraps. But whatever you do, do not allow the caliper to hang by the brake line.
04. With the caliper secured, the next item to be removed is the hub dust cap. It’s generally a press-fit part that requires only mild pressure to remove.
05. Behind the dust cap is the castle nut, which holds the bearing in place (some vehicles use a locking nut and conventional nut to secure the bearing). A cotter pin is attached to the nut and its end pins must be straightened and the pin pulled through the nut before the nut can be removed.
06. Next, the castle nut is simply loosened and removed.
07. With a little wiggling of the brake rotor, the wheel bearing should push forward. Simply pull it off the spindle, but don’t immediately wipe away the grease on it. Inspect the grease for signs of silver flecks that indicate bearing damage. If no signs of damage are visible, clean off the bearing with solvent and soapy water and check it again for pits, scoring, or other signs of damage or wear on the rollers. If none are present, the bearing can be reused—but wheel bearings are cheap, so it’s not a bad idea to install fresh ones.
08. Pull off the rotor and flip it over to access the bearing grease seal. It is easily removed with gentle prying from a flat-blade screwdriver. Replace the seal with a new one.
09. Fitting the new grease seal requires care to ensure it seats evenly. An uneven or bent seal will foster a grease leak. A large socket, length of pipe, or other item approximately the same diameter as the seal can be used, as shown, to provide even pressure when tapping the seal into place.
10. It’s time to get messy with the grease, so put on a pair of disposable latex gloves.
11. Use only wheel bearing-specific grease for the job. It is formulated for the extreme temperatures that are generated by the brakes.
12. As with the wheel bearing itself, the spindle should be inspected for metal particles or other signs of wear and damage. If none are present, wipe off the hub and apply a new covering of grease.
13. When it comes to actually packing the bearing, it’s pretty simple: Place a good-sized dollop of grease in the palm of one hand and push the bearing into it with the other, rotating and pressing the bearing into the grease several times. Make sure all sides and areas of the bearing are thoroughly immersed in the grease.
14. Next, slip the brake rotor back onto the spindle and liberally spread more wheel bearing grease around the inside of the hub.
15. The rest of the procedure is essentially a reversal of the removal steps. The bearing is slipped in place and secured with the castle nut. The trick here is to tighten the nut without over-tightening it. It should be tight, so there isn’t wobbling, but loose enough to permit easy, unimpeded rotor rotation. Generally speaking, after tightening the assembly to seat it, back off the castle nut and re-tighten it with about half as much torque as it took to seat the assembly. If you have one, check the service manual for specific torque specs.
16. Even if you’re reusing the original wheel bearing, use a new cotter pin with the castle nut. Bend the pins in opposite directions, as shown.
17. Pack the inside of the dust cap with wheel bearing grease before reinstalling it on the hub. Use a dead-blow hammer or a similar tool to prevent damaging the cap.
18. Finish up the job by reinstalling the brake caliper and wheel. That’s all there is too it—and the only items required are a couple of hand tools, a handful of bearing grease, and new bearings and cotter pins. Even if you’ve never performed the job before, it takes less than an hour to do each wheel bearing.
19. Time to hit the road. Freshly packed wheel bearings help ensure safer highway driving in vintage cars and maximizes the longevity of brake and axle components.