Jeep JK Wrangler Unit Bearing Replacement Write-Up

cozdude

Guy with a Red 2-Door
As always, great write up Eddie. I actually have these arriving tomorrow from Rockauto, will install next weekend.

just ordered 2 from rockauto myself after reading where yu got yours and when i saw the price. thanks!
 

Linebacker

Caught the Bug
Thanks Eddie for another excellent "How to photo essay." I live a long way from a dealership so each write-up gives me another measure of independence.:thumb::thumb:
 

wayoflife

Administrator
Staff member
Nice write up. It's a lot more work with locking hubs correct?
They intimidate me.

Yeah, it's a lot more work to take apart a set of Dynalock hubs and if you don't have the right tools to do it, it can be a job. But, with the right tools, it's really not so bad.
 

cis911

New member
I love this writeup, one question though. How much play is too much? I need and want one of these dials you have but need to know how to use it.
 
Last edited:

wayoflife

Administrator
Staff member
I love this writeup, one question though. How much play is too much? I need and want one of these dials you have but need to know how to use it.

Well, for a set of ball joints, radial (side-to-side) movement in the upper ball joint should not exceed 0.060" (1.5mm). Axial (up and down) movement in the lower ball joint should not exceed 0.050" (1.25mm). Of course, on our unit bearings, we were seeing 0.1" of movement which was a LOT and enough so that you could see camber in our wheels. Most of the time, your ball joints is where you will see movement and as I had mentioned, I had originally thought that's where my problem was. It was only after replacing them and still seeing camber and movement in the wheels that I realized my unit bearings were bad.
 

gtony12

Caught the Bug
Hey Eddie,

Great write :yup:, thank you for posting. I love wrenching on my jeep myself :yup:, but I always get a little nervous for the first time doing the repair. :rock:
 

Stegertime

Caught the Bug
Excellent write up. The fear of death wobble is ever-present so anything I can do in my garage to help before hitting the road is perfect, thanks Eddie!:D
 

olram30

Not That Kind of Engineer
Great write up, but recommend installing SKF hub bearings part #BR930612.

i looked that part number on amazon and says it doesn't fit my 2012. timken on amazon are 105 bucks, that part number you gave is 115 from rock auto.
looked into this, skf part number is #30839. i guess there are different part numbers for 11 and up.
 
Last edited:

wayoflife

Administrator
Staff member
Great write up, but recommend installing SKF hub bearings part #BR930612.

Welcome to WAYALIFE! I see that you've been on here for a while now but glad that you've finally decided to post up. As far as the SKF hub bearing goes, is there a specific reason why you would recommend it over Timken?
 

StormJKU

New member
Well, for a set of ball joints, radial (side-to-side) movement in the upper ball joint should not exceed 0.060" (1.5mm). Axial (up and down) movement in the lower ball joint should not exceed 0.050" (1.25mm). Of course, on our unit bearings, we were seeing 0.1" of movement which was a LOT and enough so that you could see camber in our wheels. Most of the time, your ball joints is where you will see movement and as I had mentioned, I had originally thought that's where my problem was. It was only after replacing them and still seeing camber and movement in the wheels that I realized my unit bearings were bad.

Great write up, thanks.
So on the written above. Is there any way I could tell if it is a ball joint or a bearing?
Recently I noticed some camber on the right wheel. When I lifted the wheel, I noticed some freedom while wiggling the upper side of the wheel, none on the lower, when I removed the unit bearing I noticed the lower was moving freely by hand with no resistance on it's axis but no freedom, so I replaced it as well.
Is there a way to figure which of these item is faulty and which one before taking things apart?

-N
 

cozdude

Guy with a Red 2-Door
Great write up, thanks.
So on the written above. Is there any way I could tell if it is a ball joint or a bearing?
Recently I noticed some camber on the right wheel. When I lifted the wheel, I noticed some freedom while wiggling the upper side of the wheel, none on the lower, when I removed the unit bearing I noticed the lower was moving freely by hand with no resistance on it's axis but no freedom, so I replaced it as well.
Is there a way to figure which of these item is faulty and which one before taking things apart?

-N

im no expert but i have a question. how many miles are on your jeep? what size tires are you running and for how long? did you have gussets welded on your C's?
 

StormJKU

New member
im no expert but i have a question. how many miles are on your jeep? what size tires are you running and for how long? did you have gussets welded on your C's?

1. About 55k miles
2. 35"
3. For about 10k miles
4. Yes I do.

Thanks
-N
 

cozdude

Guy with a Red 2-Door
1. About 55k miles
2. 35"
3. For about 10k miles
4. Yes I do.

Thanks
-N

I with all that being said I would replace your ball joints as they are the ones prob shot. I had mine replaced at 20,000 miles. If you want a good cheap set look at Crown HD ball joints. You can get both sides for about $100. If your still having issues then I would do the unit bearings. I got the Timkins in the write up for $175 for both sides. One side from mopar is $167.
 

StormJKU

New member
I with all that being said I would replace your ball joints as they are the ones prob shot. I had mine replaced at 20,000 miles. If you want a good cheap set look at Crown HD ball joints. You can get both sides for about $100. If your still having issues then I would do the unit bearings. I got the Timkins in the write up for $175 for both sides. One side from mopar is $167.

Thanks for your advice.
As noted before, I already replaced the ball joints, I actually used Alloy USA HD ones.
My question was related to figuring the faulty items without removing the wheel. The reason I'm asking is because I found the lower ball joint was faulty when I was replacing the upper one. Could not figure this before- hence, it might be that the other wheel has also faulty parts but I can't diagnose it.

-N
 

cozdude

Guy with a Red 2-Door
Thanks for your advice.
As noted before, I already replaced the ball joints, I actually used Alloy USA HD ones.
My question was related to figuring the faulty items without removing the wheel. The reason I'm asking is because I found the lower ball joint was faulty when I was replacing the upper one. Could not figure this before- hence, it might be that the other wheel has also faulty parts but I can't diagnose it.

-N

There was no mention of you replacing the ball joints in your previous posts which led me to believe they were bad. Ok let me ask you this then, did you install the new alloy ball joints before or after your gussets were welded on?
 

OverlanderJK

Resident Smartass
There was no mention of you replacing the ball joints in your previous posts which led me to believe they were bad. Ok let me ask you this then, did you install the new alloy ball joints before or after your gussets were welded on?

Won't really matter with the aftermarket ball joints since the plastic ring, that normally gets fried on the stock ones, isn't there. I think I know where your going with that.
 

cozdude

Guy with a Red 2-Door
Won't really matter with the aftermarket ball joints since the plastic ring, that normally gets fried on the stock ones, isn't there. I think I know where your going with that.

Yea just was trying to cover all basis. Can't the heat still mess them up tho?
 
Top Bottom