Tuesday, December 1, 2020

Repacking C3 Corvette Front Wheel Bearings

The 1976 Chevrolet Service and Overhaul Manual Supplement, specifies repacking tapered front wheel bearings every 30,000 miles. There is no specific recommended mileage or time frame for replacing the bearings, so that would be at the mechanic's or Chevrolet's Service Dept. discretion.

If the necessary tools are available, this is a DIY job for the more advanced and/or ambitious shade-tree mechanic.

It is not necessarily difficult, but it is a messy one. Remember, you'll be dealing with automotive grease, road grime, and brake pad dust to name a few.

Gloves, safety glasses, and a respirator are must-have items.

The first order of business is to get the car off the ground, and my QuickJack Portable Lift proved one more time what a great investment it was.

With the car lifted, I started by removing the passenger side front wheel.



When you look behind the caliper, you'll see four bolts. You want to remove the two that secure the caliper to the bracket (red arrows in photos below). The other two keep the two halves of the calipers together. DO NOT loosen or remove those.


With the bolts out, I removed the cotter pin that secures the brake pad pin (red arrow in the photo below).


I prefer not to reuse cotter pins since they are prone to failure. I purchased a 555 cotter pin kit for about ten bucks, so I should have plenty for years to come.


Next, I removed the pin and then carefully slid the caliper off the rotor. I then removed the two brake pads, set them aside, and hung the caliper behind the rotor and out of harm's way with a rubber bungee cord hooked to the coil spring.

I used a pair of Channellock pliers to remove the dust cover.


From the lack of rivets, it is obvious that my front rotors were replaced at some point by the previous owner. If yours still has the original rivets, do not worry as the whole assembly comes out together and that has no effect on repacking and/or replacing the bearings.


The castle nut that secures the rotor to the spindle also has a cotter pin that has to be removed.

The spindle castle nut should not be very tight and you will need a 1¼ socket, but you can also loosen it with a crescent wrench or even a pair of Channellock pliers.

With the spindle nut out, I gently pulled outward on the rotor to remove the washer first, then the outer bearing. With those out, I removed the rotor and placed it on my workbench to remove the inner seal and bearing.


I prefer to use a seal puller to remove seals without damaging the surrounding area. Even though I will replace the seals regardless, I did not want to scratch or score the hub, something that can happen if you use a screwdriver, for example.


Seal pullers are inexpensive and effective. Once the hook is in place, a good tug will release the seal.



And here it is. I gave it a good cleaning so I could bring it with me to the auto parts store to make sure the ones I ordered are the exact same size. I hate bad surprises when I am getting ready to put things back together.



The two photos above show the inner bearing. Timken, in my opinion, makes some of the best bearings available.




The bearings, castle nut, and washer got a nice 6-hour bath in Gunk Parts Cleaner. The solution removed the old grease and dirt leaving the bearings ready to be repacked.


I avoid reusing cotter pins whenever possible, and having an assortment kit is a good idea. They are inexpensive and 555 pieces will last you a very long time.

With the bearings soaking in the parts cleaner, I turned my attention to the brake pads. A thorough visual inspection revealed no unpleasant surprises and, besides dust and dirt, they look like new.




I consider dirt the enemy, so I cleaned the metal backing plates with a wire brush with excellent results. It's a good idea to wear a dust mask or respirator while doing this just to be safe.




The three photos above show the before and after. I will apply a thin layer of caliper lube to the areas that contact the pistons, as well as the pad pin.


The photo above shows some of the components clean and ready to be reinstalled. I still have to pick up the new seals and may also get new grade-8 bolts and washers if I can find the right size. I also trimmed the cotter pins to size.


The bearing races are in perfect condition and will be reused. Proper maintenance ensures a long service life.



The bearings cleaned up nicely and I allowed them to air-dry for a few hours before repacking them. Any remaining dirt will be expelled when the bearings are repacked.

And speaking of repacking bearings, there are a couple of ways to do this.

One is the old-school method of applying a big dollop of grease to the palm of your hand and pressing the edges of the bearing while you "scoop" little bits of grease that get packed between the rollers and the cage. 

It is time-consuming and not the best way of achieving this task, but if done correctly, it gets the job done, albeit very slowly. If you choose this approach you may want to wear nitrile gloves.

The second method, using a bearing grease packer, is a far better alternative and the one I chose. There are a couple of different versions of this tool and I prefer the original since it's a lot cheaper and it allows you to use a grease gun which, I believe, allows the process to go faster. You can see it in action in the video below.

And while speaking about grease, there was a ton inside the hub, in the area between the two bearing races, which in my opinion is not only a waste but against factory recommendations. The spindle goes through the hub and is centered in place by the inner and outer bearings so it does not touch any other surfaces.


Above: 1976 Chevrolet Service and Overhaul Manual Supplement.
(0-14 General Information and Lubrication)

After removing the excess grease, I cleaned the area and applied a light coat to protect the metal.


Also, if you need to remove the bearing races, the red arrows in the photo above show the small indentations in the hub that allow you to drive out the outer race with a drift punch. 

The blue arrows show the indentations for the inner bearing race and you drive that one out from the other end.

With my new bearing packer, inner seals, and new Grade-8 bolts and washers in hand, I started by packing the bearings. I used Lucas Red "N" Tacky grease since it had excellent reviews.


The bearing packer is self-explanatory and you can see it in action in the video at the end of this article. By the way, if you find the video helpful, please hit the "like" button. You can also subscribe to my YouTube channel for more C3 Corvette content.


Since I hate to waste stuff, I reused the excess grease in the hub to prime the packer.



The photo above shows the outer bearing before packing. The packer ensures grease gets into every nook and cranny which is crucial.

The next two photos show the inner bearing sitting in its race and the grease seal ready to be tapped in place. I chose to drive it in by tapping with a hard-rubber mallet but you can also use a piece of wood that spans the seal from side to side along with a heavy hammer.



The photo above shows the seal properly seated.

I also bought a bottle of CRC Disc Brake Quiet and I applied a generous coat to both brake pad's backing plates. I allowed the product to cure for about 30 minutes before reinstalling the pads in the caliper.

And yes, you only need to coat the area where the piston makes contact with the pad.



I also applied a coat of Sil-Glyde Brake Lube to the outside edges of the caliper pistons. Overkill? Maybe. But nothing's worse than squeaky brakes.


And even the dust cap got the presidential treatment with a good cleaning, sanding, primer, and a couple of coats of silver paint.

I think the video below helps illustrate and understand the complete process a lot better.

I hope you find both this article and the video helpful.


But before I go... 

I started disassembly of the driver's side caliper and rotor right after I finished the right side front wheel, and discovered that the inner grease seal had failed, most likely due to the excess grease packed inside the hub.


The photo above offers clear proof of grease seal failure. The inside of the rotor was covered with a layer of burnt, dirty grease.


And you can also tell from looking inside the hub. The bearing race and the bearing looked okay, but I replaced them, just to be safe.

I think this emphasizes why it is so important to check and service these components every 30,000 miles.

As always, thank you for following my 76 Vette Blog!








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