86 Cherokee Wheel Bearing Replacement

The Problem

From 37 to 46 MPH a really annoying pulsating noise would rattle your brain. Then from 66 MPH and up an even louder high pitched hum would start. It was really annoying.

Possible Solutions

I could either pay someone to replace it, or do it myself and possibly learn something in the process. I called around and was told it would cost around $300 to replace the bearing. That is a lot of money just to get rid of a noise. I found the entire bearing and hub assembly was only around $65 from a local parts store, so I figured I would try fixing it myself.

Tools Needed

Pictured

• PB Blaster - I probably wouldn't have been able to get any of the bolts out without this stuff.
• LPS3 - for preventing the bolts from getting all rusted and corroded again
• 3-Jawed Gear Puller - for pulling the bearing/hub out of the steering knuckle
• Torque Wrench
• 1/2 Breaker Bar
• 1/2 Ratchet
• 36mm 6 point Socket - for the hub nut (borrowed from Advance Auto Parts)
• T45 Torx Bit - for the brake caliper pins
• 13mm 12 point Socket - for the hub retaining bolts
• 19mm 6 point Socket - for the lug nuts
• Pliers

Not pictured

• Jack
• Jack Stands
• Hammer

Procedure

The first thing was to break the hub nut loose. To get at the hub nut I had to first take the wheel off and remove the plastic cap from the center of the wheel. Then remove the cotter pin and the nut retainer from the end of the axle shaft. This allowed me to get to the hub nut to break it loose. It was supposed to be torqued to around 175 ft-lbs so I put the wheel back on and set the car back on the ground to prevent the nut form turning as I break it loose. The nut felt like it was only on at around 50 ft-lbs and came off without a problem.

After removing the wheel again I took the brake caliper off by unscrewing the 2 pins holding it on with the torx bit. The rotors were replaced on this car two years ago for inspection so the caliper came off really easily. Then the rotor, pads and clips. This gives you access to the bearing/hub assembly.

To remove the hub you have to remove the 3 12 point 13mm bolts from the back of the steering knuckle. You can only see 2 of them in the pictures above. Once they were juiced up they came out pretty easily too.

From what I read online and in the service manual the whole hub assembly should just slide out of the knuckle once you remove the 3 retaining bolts in the back and the hub nut in front. It didn't. It was pretty rusty and needed some serious persuasion to come out. I had to go back to the parts store and get a gear puller. Even with the puller I had to juice it up over a couple of hours and smack it around with a hammer and block of wood to get it out.

The knuckle looked pretty rusted when I finally got the hub assembly out so I used some sand paper to clean it up a little before putting the new assembly in.

New and improved, old and busted...

Before putting the new hub in I greased the splines of the axle shaft, the knuckle, and the new bearing side so it might come apart easier in another 120,000 miles if I have to do this again. Notice I have the brake shield on backwards in the picture...I didn't notice this until I had it all back together and tried putting the rotor back on.

Once I got everything back on (the correct way), I bolted the hub on and torqued the bolts to 75 ft-lbs. Then the clips and the inside brake pad went on. Then the rotor and outside pad. Then the caliper, torquing the pins to 20 ft-lbs. At this point I did a quick check of the brakes. I looked around to see if brake fluid was dripping from anywhere, thankfully it wasn't. Then I stepped on the brake pedal so the caliper would align itself correctly and to make sure I still had a firm pedal. The wheel went on next and then I put the car back on the ground to torque the hub nut. My torque wrench only goes up to 150 ft-lbs so that is what I used instead of the 175 the book recommends. Then I took the wheel off and on again to put the plastic cap back in. Lastly I went for a spin around the block to see if the noise is gone and to see if the wheel falls off. I'm going to drive it around town for a while and then re-torque all the bolts once everything has a chance to settle. And I'd rather a wheel fall off while I'm tooling around town than while going 70 MPH on the highway. We'll see.

Final Result

Instead of spending $300 I spent around $100 ($25 of which was the puller) and learned a lot about my car. I haven't been very comfortable in the past taking on big projects on my car, but I'm getting braver with each one. This was by far the biggest and most complicated, but I'm starting to learn that as long as I have the right tools and the book, I can probably do anything needed to keep this car functioning.