Jeep JK Wrangler Unit Bearing Replacement Write-Up

wayoflife

Administrator
Staff member
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Running big heavy off road tires on wheels that have a lot less back spacing will put a lot more strain on your unit bearings and that will cause them to wear out prematurely. Worn out unit bearings can cause your wheels to look like they have camber to them and much like bad ball joints, can allow for enough movement to cause death wobble. Fortunately, replacing them costs less than $200, is a relatively easy job and is one that can be done at home with a few simple tools. All you have to do is make sure you have the tools listed (can be found at most any auto parts store) and follow the instructions below.

What You Will Need:
Timken HA590242 Wheel Bearing and Hub Assembly
• 12-Point 13 Socket/Wrench
• 19, 21, 36mm Sockets/Wrenches
• Impact Wrench or Breaker Bar
• Ratchet
• Pry Bar
• Torque Wrench
• 2 lb. Hammer
• Wire Brush
• Red Lock-Tite
• Bungie Cord
• Zip Ties
• Brake Cleaner


Why You'd Want to Replace Your Unit Bearings:
After installing a new Dynatrac ProRock 44 and ProSteer Ball Joints, I noticed that my wheels still had a bit of camber to them when sitting on the ground and, after doing a check with a dial indicator, I was able to confirmed that my old unit bearings were in need of being replaced as well. Below is a short video clip showing just how much movement we were seeing in our unit bearings.


Instructions:
Here is a shot of what your new Timken wheel bearing and hub assembly or, what is also known as a "unit bearing" will look like. As you can see, it will come complete with a speed sensor already installed on it.
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1. To begin this job, use a 19mm deep socket to remove the 5 lug nuts securing your wheel to your axle. Remove the wheel and set it aside.
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2. Using a 21mm socket, remove the 2 bolts securing the brake caliper to the knuckle. These bolts will have been installed with Lock-Tite and so you may need to use a breaker bar to get them started. This is where the lower bolt is located.
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And this is where the upper bolt is. The space here is tight and you may find it easier to use a 21mm box wrench for this job.
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3. Remove the speed sensors from the 2 retaining clips mounted on the knuckle as shown. The rubber fittings are just wedged in place and you will just need to push down on them.
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4. Use a bungie cord or zip ties to hang your brake caliper from the frame. You do not want to let the caliper dangle from it's brake line. Also, try to be mindful of not letting the brake pads fall out of the caliper.
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5. If you look behind the frame rail near your coil and shock tower, you will find the speed sensor wiring harness plug. Slide the red lock tab out and and disconnect the plug.
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6. Remove your brake rotor. If this is your first time doing this, you may find a couple of assembly washers attached to the wheel studs holding it in place. If this is the case, use a pair of needle nose pliers to pry them off. You will not need to reuse these so you can just throw them away.
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7. Remove the axle hub nut using a 36mm socket. If you do not have an impact wrench, place a pry bar between the wheel studs while using a breaker bar to free the nut (see step #14 for an example pic).
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8. Using a 12-point socket or box wrench, remove the 3 bolts securing the unit bearing to the knuckle. 2 of the bolts can be found on the back.
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And, there is one on the front as shown.
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9. Loosely reinstall the axle hub nut onto the stub shaft and then give then give it a light tap with a heavy ballpeen hammer. This should be enough to free your unit bearing from the splines of the stub shaft. If you live in the rust belt of America, you may find it necessary to use a puller to separate them.
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10. Make note of the how the brake dust shield is positioned and then remove the old unit bearing from the knuckle and stub shaft.
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11. Route your new speed sensor wiring through the dust shield and then install your new unit bearing onto the stub shaft and knuckle.
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12. Clean your unit bearing bolts with some brake cleaner and a wire brush and then apply a drop of red Lock-Lite on them.
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13. Using a 12-point 13mm socket, secure the unit bearing in place and tighten the 3 bolts to 75 ft. lbs. of torque.
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14. Install the axle hub nut and tighten it to 100 ft. lbs. of torque. To do this, place a pry bar between the wheel studs while using a breaker bar to tighten the nut.
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15. Route your new speed sensor wire through the knuckle and secure it to the 2 clips mounted on the knuckle.
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16. Plug the speed sensor wire back into the main wiring harness located behind the frame rail.
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17. Thoroughly clean your brake rotor with brake cleaner and then install it onto the wheel studs.
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18. Apply a drop of red Lock-Tite to the caliper bolts.
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19. Reinstall your caliper onto the knuckle and rotor and secure it in place by tightening the 2 bolts to 120 ft. lbs. of torque.
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20. Reinstall your wheel and secure it in place by tightening the lug nuts to 95-100 ft. lbs. of torque and you're done.
 

Fat Man

New member
Nice! I am doing this to my 2003 TJ this coming week. Except for the speed sensors it is pretty much the same exact deal, even the torque specs.

Why red Loctite, though? In the TJ world we generally use blue for just about anything that needs to use a threadlocker compound. Or course, we use more than a small dot, so I guess it works out the same in the end. Or is there a specific reason? Please de-ignoramous me! Do JK specs call for it rather than blue? Just curious... ;-)

Wade
 

wayoflife

Administrator
Staff member
Nice! I am doing this to my 2003 TJ this coming week. Except for the speed sensors it is pretty much the same exact deal, even the torque specs.

Why red Loctite, though? In the TJ world we generally use blue for just about anything that needs to use a threadlocker compound. Or course, we use more than a small dot, so I guess it works out the same in the end. Or is there a specific reason? Please de-ignoramous me! Do JK specs call for it rather than blue? Just curious... ;-)

Wade

All the bolts on the JK use blue as well, just a lot more of it. I like to use red because you can use a lot less of it and get the same results and it does better with higher temps. At least, that's what I have found but if you'd rather use blue, by all means, please do as I'm sure that's what the dealerships would use.
 

cozdude

Guy with a Red 2-Door
Thanks for this Eddie! I didn't know that that little movement in the unit bearing means it's bad!?!! That means both of mine are shot! Time to order the ones one listed and return the mopar one since it was $167 for one lol
 

wayoflife

Administrator
Staff member
Thanks for this Eddie! I didn't know that that little movement in the unit bearing means it's bad!?!! That means both of mine are shot! Time to order the ones one listed and return the mopar one since it was $167 for one lol

Yeah, when I was shopping around for a pair, I saw that too. You can get cheaper ones than the Timkens I got but, Timken makes quality bearings and so, I decided to go with what I know.
 

cozdude

Guy with a Red 2-Door
Yeah, when I was shopping around for a pair, I saw that too. You can get cheaper ones than the Timkens I got but, Timken makes quality bearings and so, I decided to go with what I know.

I'm deff going to order them then and return this mopar to Quadratec. I have had this sitting in my garage for almost 6 months now but never installed it lol. Good thing I didn't cause now I'm about to save some money.
 

BTkillerr

Member
questions

Great write up! A couple of questions. How are you checking the play? Pushing down on the bumper? Prying up on the tire?

Last question...I looked but didn't see. Is there a write up on doing the front ball joints anywhere? I think I need to replace mine.

Thanks,

BTKillerr
 

sc_rhino

Member
After installing a new Dynatrac ProRock 44 and ProSteer Ball Joints

Hey Eddie, was curious if this is a pr44 w/arb or are you referring to the elocker version. I'm on the fence on which one to go with but will probably go with arb. Any problems with the elocker?
 

wayoflife

Administrator
Staff member
Great write up! A couple of questions. How are you checking the play? Pushing down on the bumper? Prying up on the tire?

Last question...I looked but didn't see. Is there a write up on doing the front ball joints anywhere? I think I need to replace mine.

Thanks,

BTKillerr

The unit bearing in question was bad enough that I could make it move just by rocking by hand it at the 12 and 6 position. However, if you jack up your wheel so that it's just off the ground, you can use a prybar to lift up on the tire to create the same movement.
 

wayoflife

Administrator
Staff member
Hey Eddie, was curious if this is a pr44 w/arb or are you referring to the elocker version. I'm on the fence on which one to go with but will probably go with arb. Any problems with the elocker?

As much as I would have preferred to have gotten my ProRock 44 with an ARB, I ended up getting one that I could recycle my Rubicon e-locker and shafts. I needed a new axle in a hurry and this was all I could get. You are definitely out to save a lot of money going this route but you'll have a stronger setup with an ARB. Still, I have not had any problems as of yet with this setup.
 

mjbjw

New member
Great item by item walk through...good job my friend.

Sent from my SAMSUNG-SM-N900A using WAYALIFE mobile app
 

QRS

New member
As always, great write up Eddie. I actually have these arriving tomorrow from Rockauto, will install next weekend.
 

frenchjk

Caught the Bug
thanks

Fantastic........keep it up, great write up! (esp here in europe we have heavier Diesel engines and equally large/heavy wheels so that goes a long way to stress the unit bearings.
 
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