It was the entire hub assembly replacement + labor.

 

So I'm still not sure if what I need to do is replace both wheel hubs or something else... ?

 

Disconnect and make sure there's no dirt in the sensors and reconnect them again, open the abs box in the engine bay and clean it out if its dirty. If that doesn't help find a trusty mechanic.

 

Is it doable without lifting the car up in the air?

 

First, you need an ODBII scanner that can read the ABS computer (not all ODBII scan tools can do this). A good one can read codes that were thrown but may not be illuminating that ABS light at the moment. Usually the code will point you towards the problem wheel. I've seen a problem be a severed wire (once), usually it's the hub assembly that houses the ABS sensor.

Again, I highly recommend a Timken bearing. It's made here in the U.S.A., they have a great track record for reliability. Using RockAuto, I can typically get a Timken bearing for a W-Body car for $100 to my door. Saving $10-$30 to get a cheaper one is NOT worth it. I've gotten good at doing the front bearings on GM FWD cars (about an hour flat), but I certainly don't want to do it in 1.5 years because I tried to save a couple dollars per bearing (been there, done that, won't do it again).

Removal is simple, BUT, IMO, if you don't have access to a tool called an Air Hammer, DON'T BOTHER! The hub is "pressed" into the steering knuckle, the air hammer lets you quickly and easily pop it out by working it into the sides (after you get the 3 bolts on the back of the hub/knuckle removed and the axle nut). If you try pounding the hub out, get ready to spend some more quality time and a work out. GM recommends a "puller" for the job. I have never used one, never had it available, but the air hammer has never failed me.

The ABS sensor is in the wheel bearing on these cars and it's a sealed unit (the ABS sensor is not external and it's not serviceable).

You can check the wiring. I believe you can do the fronts without lifting the car, just turn the wheels hard one way, inspect one side and then turn hard the other way and inspect the other side.

 

You can do this without air tools. Obviously, an air hammer would be preferred, but it can be done with hand tools. Once the brakes were removed, I removed the axle nut and 3 mounting bolts, whacked the outer perimeter of the hub with a regular 16oz hammer, and it slowly worked its way out. The center of the hub broke off/stayed in the steering knuckle, but was easily removed by tapping the rear of the hub with a hammer & screwdriver. Biggest tools I used were a 1/2 inch drive breaker bar and a hollow jack handle for extra torque removing the bolts.

If your car has high miles and the hubs are original, I would personally change them anyway, now that the sensors are in question. As Maniac said, the abs sensors are built into the hub assembly and cannot be accessed.

 

how hard is it to replace a wheel bearing? this might be my summer project because my abs and tracktion light are also on

 

Yeah I have about 93k miles. I was planning on replacing them both anyways, they've been through some harsh weather. I just don't like spending $150 for some hubs. Sigh... the things we do for our cars...

 

As I mentioned towards the end of my post, GM recommends the use of a puller to remove the hub (which is a hand tool). I've never used it.

As for pounding it out without an air hammer all depends on how hard that thing is in there. I've had a couple hubs that even with the air hammer were difficult to remove (I could not imagine using the puller or pounding them out by hand).

What I was providing is simply a recommendation based on my experience for the easiest way to accomplish the job at hand.

Not very hard with the right tools and knowledge. This is one of many threads discussing this topic.

 

Agreed. I was just adding tips for those of us that do not have access to air tools...I really wish I would have invested in a good set before I decided to do some of the projects I've done.