The monster in the car

My daughter’s 2010 Cobalt was making terrible metallic growling noises as it drove up our driveway. It didn’t take much troubleshooting to diagnose a sorely overdue front brake job. Pads and rotors. Easy.

Horror! There is literally no brake pad left on one of these. Just the metal plate that the pad is affixed to. I’m not really sure how the car was stopping! Yiiii!
Here you can also see the effects of delaying replacement of brake pads. This is the metal on metal scraping noise you hear. The lack of pad material grooves the rotors which in turn doubles or triples the cost of the job because now these need to be replaced.

After the front brake job, I drove the car and it was responsive to the brake pedal but there was still something clearly amiss. The car still had a “growling / grinding” metallic sound when turning the wheel right at above 5 mph.

My daughter had to go to home. I was tired and the car was at least operational and could stop if there were any traffic lights or stop signs on the way home and someone opted to proactively depress the brake pedal. Time for some research.

Google brought me to wheel bearings. Wheel bearings hold your vehicle’s wheels in position while allowing them to spin. This is a “newish” car (2010) so the wheel bearings are integrated into an assembly with the ABS wheel sensor called a wheel hub.

At first it seemed like replacing this part was digging a bit too far into the car but the more I thought about it the procedure basically was just taking 3 more bolts out and unscrewing the wheel shaft. Besides, I had already done the brake job so I was familiar with this area of the car.

It was a good excuse to buy a massive 200ft lb. torque wrench and I got the 30mm 1/2” socket for the axle nut. It does look manly carry a two and a half foot wrench out of the hardware store.

While I really liked the knurled finish on the handle of the Kobalt brand, I decided on the Craftsman wrench mainly because the numbering was red on black instead of just stamped chrome with no visibility. Both were 89.95 but as one gets older visibility becomes a much bigger priority when working with precision tools. The one thing I don’t like about Craftsman these days is that the warranty is 90 days on this tool versus the lifetime that Sears used to carry. The Kobalt wrench had a full year.

The wheel hub was aftermarket “Master Pro” brand and cost 109.99. However, you can get OEM ones that are maybe slightly better for about $160 if that suits your budget.

I like O’riley. The employees at my local store seem to know more than most of the big box auto stores in town. They also accept my used oil for recycling. So far the parts I have purchased from O’riley have worked great.

I fretted a bit about the logic I saw on the internet about diagnosing which bearing might be bad based on all kinds of silliness about inside turning and the opposite thrust direction etc. …a lot of YouTube videos of various hacks trying to figure out which bearing was bad.

Turns out all you have to do is jack up each side and grab and shake the wheel side to side and up and down. If the wheel wobbles…= bad wheel hub / bearing.

Besides the torque wrench, here is basically what you need.
Undo the rotor and caliper assembly
Then further unbolt the wheel hub. Usually 3 or 4 bolts. Unscrew the axle / shaft nut. This one was 30mm. I used an air ratchet to speed things along.

Here is the failed wheel hub. It felt like it had some play in it but not nearly as obvious as when I had the wheel jacked up and was rocking the wheel back and forth. A little bit of
Scratchiness was heard when spinning the hub after removal.

Reverse everything you took off and make sure you plug in the ABS sensor and bolt the dust shield behind the wheel hub. I highly recommend using a torque wrench to not over stress the bolts. The axle nut was torque rated to 155 ft. lbs. Tighten a bit, put the tire back on (100 ft lbs per nut), lower the car, and do final torque on the axle nut with the tire touching the ground.

The test drive was fantastic.

The car was SILENT!

Then I decided to do the rear brake shoes! My words for the next 2 hours as I did one side of the car broke the silence. More than once. 🙂

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