Cleaning and Packing Front Wheel Bearings

Written by Don Stewart | 31 January 2007

The October 2005 issue of Pony Express included a Pony Tricks article devoted to replacing front wheel bearings in a first generation Mustang. There was a brief reference to lubricating the bearings but the procedure itself wasn’t covered. This Pony Trick will explain how to clean and lubricate them. To do the job, the front tires need to be jacked up off the ground and the wheel hubs removed from the spindles.

If necessary, refer to the October 2005 article to refresh your memory on how to remove the bearings. It’s very important to prevent the bearings from becoming contaminated with dirt so when you remove them, place them on a clean surface; a piece of cardboard or a short board works well. It’s also important to keep the bearings and hardware from one hub completely separate from the same items removed from the other hub. If both sides are removed at the same time, use two pieces of cardboard or two boards to keep things separate.

Remove the nut and washer from the spindle, remove the outer bearing from its race and slide it off the spindle, and finally, remove the hub from the spindle and pry the seal out of the hub behind the inner bearing. Some procedures say to use a wooden dowel from the front side of the hub to reach through the hub and then strike the dowel with a hammer to drive the inner bearing and the seal from the hub. Usually the same procedures say to reuse the seal during reassembly unless it’s damaged or worn out. Seals are inexpensive so my recommendation is to use the procedure that says to pry the seal from the hub. That will damage the seal sufficiently that it can’t be reused. That’s a good thing because it’s difficult to measure wear or to see minor damage that might allow the seal to leak, if re-used. When the seal has been removed, take the inner bearing out of its race.

Now that the bearings are out of the hub, everything (bearings, spindles, wheel hubs, races, dust caps, washers, and nuts) needs to be cleaned of old grease. You can purchase a small bearing cleaning device or you can use a small container with solvent in it. Whichever you choose, the idea is to remove all grease from each bearing and its cage. Also disolve all grease from the other parts. When this has been done, inspect the bearings and races for overheating or damage. Either condition means a bearing assembly is no good and needs to be replaced. For more information, refer to the October 2005 Pony Tricks article.

When you’ve completed your inspection, it’s time to buy new seals and any replacement bearings that you need. Also, if you don’t already have it on the shelf, buy wheel bearing grease. Be sure the grease is specifically for wheel bearings that use roller bearings, not ball bearings. And don’t be afraid to buy grease formulated for disc brake cars even if your car has drum brakes. The disc brake grease has properties designed to work at the higher temperatures generated by disc brakes so it’s an excellent choice for cars with drum brakes, as well.

At this point, the fun begins. I always find it more gratifying to put something back together and that’s where we’re at in this Pony Trick.

First, with clean hands, take a small amount of grease and put a very light coating on the spindle and on the surface at the back of the spindle where the grease seal runs. The key word here are “very light coating.” Cover the surface completely but with the lightest smear you can apply. The coating serves to protect the surfaces and to facilitate reassembly. After completing that task, put a light smear on the four bearing races. Make sure the surface of each race is completely covered but keep it light, no gobs of grease.

You can put a light smear of grease inside the bore of the hub if you want to but it isn’t necessary. If you choose to do so, keep it light. Grease inside the hub does not serve as a source of lubrication for the bearings so it would only be there to protect the surface. Excessive grease in this location can sometimes work its way past the grease seal and wind up on the brakes, an unintended consequence that you absolutely want to avoid.

All of the prep lube has been done so now it’s time to pack the bearings. You can buy a bearing packing tool but in my opinion, the time required to set it up, use it, and then to clean it up when the job is completed makes it advisable to just go ahead and pack the bearings by hand. We’ll start with the inner bearings.

The way I like to pack bearings is to push the bearing cage into the tub of grease and while it’s in there, work as much grease into the cage as possible using my fingers. Pull the cage out of the grease and continue to work grease into it until all of the open spaces around the bearing rollers are full of grease. Finish up by smearing a medium coating of grease over the surface of the rollers. After each bearing is packed, place it in its race.

When both inner bearings are sitting in their races, clean your hands and install the grease seals either with a tool designed for the job or a large diameter brass drift and a hammer. Be patient, if you’re using the drift and hammer method. The seal-cage is slightly oversize and will resist installation. When it starts, tap it into the fully seated position in small increments by repeatedly working your way around the outer edge. Install the hub on the spindle after the seal is seated. Be careful to not damage the seal.

The outer bearings are next and the packing procedure is exactly the same. When the first bearing is packed, slide it over the spindle, pick up the washer, put a light smear of grease on it, and slide it over the spindle with the tab lined up in the keyway. Finally, pick up the nut and thread it onto the spindle as you also smear a light coating of grease on its surfaces. With the outer bearing in place in its race, hand tighten the nut. Repeat the procedure on the other side of the car.

The last steps are to adjust the bearings , insert a new cotter pin, and replace the dust cap. Don’t intentionally put any grease on the inside or outside surfaces of the dust cap.

There are a couple of precautionary notes. First, it’s essential to adjust the bearings correctly. Refer to the October 2005 Pony Tricks article for the procedure. Secondly, cleanliness throughout the repacking procedure is important to prevent premature bearing failure caused by dirt contamination. Never put parts on a dirty surface, make sure dirt doesn’t contaminate the grease, have enough lint free clean rags on hand to do the cleaning, and finally, keep dirt wiped off your hands.

If bearings are serviced correctly, they’ll last a long time. Unless a failure occurs, the service interval usually coincides with brake replacement.