resharp001

So, most of the videos on the Tube showing failed unit bearings look so obvious that my wife could tell something ain't right; However, he that likes to post a lot of videos, shows using dial indicator to show just bit of play. I'm starting to question my unit bearings a bit as I roll up on 80k miles and 5.5 years of use, the last 3 on 37s. For you guys that have replaced unit bearings, were you're toasted to the point they were wobbling all over like a lot of these youtube vids, like this -



and here is edwardo with his dial indicator (maybe that is more than it looks but it's just the zoomed so much so less reference) -

When I'm pushing on my tires, if I feel anything at all, I just wonder if it's give in the rubber or my hands....that's how little I feel.

resharp001

Just thought about the fact that I posted this in Modified, but probably should be in Stock sub-forum. Mods can move it if need be. I guess was just thinking the biggest reason these get eaten up is due to heavier modding/tires/wheel offsets, etc.

resharp001

Uploaded videos using dial indicator tonight. First vid is driver's side and not super great in regards to seeing the dial, but it is clear the variance is about swinging about 20, which is 4X greater than my passenger side which has a variance of 5-6 (second video). Anyone have an opinion? From that result, I'd at least say the driver's side is going bad, just not sure if that is bad enough to start causing an issue.

https://youtu.be/jJkNIqiJrmo

https://youtu.be/uYpSE53-oeg

ronjenx

The dial indicator is quite far out on the radius. 0.020" at that distance doesn't seem like much.

Can you feel the movement? If the unit bearing is bad, I would think you would feel the "clunk" at the ends of the travel.
Also, see how the bearing feels when you rotate it by hand, with the wheel removed.

resharp001

Thx for the comment ronjenx. I've not dealt with a bad unit bearing before, so this one in particular is kinda new territory for me. Passenger side feels pretty solid. The driver's side I was having a hard time telling if it was all in my head or not. seeing that movement, I started focusing on it, and I can indeed see the wheel moving a bit, and I can feel it, just a little bit, but definitely not solid. Revisiting Eddie's video above, it seems like twice as much movement as he's showing. I can't tell so much when just turning it with no wheel on, but when driving, something is definitely not right when going over some rough road, and I've now just rebuilt both ball joints, it's not my TB, DL, or TR, so I'm down to either steering box or unit bearings really.....and I'm really thinking it's this driver's side unit bearing now.

Rednroll

When my driver side bearing failed, I hadn't inspected it prior to replacement so I don't really know how much movement there was in it. I was just driving to work one day on the highway and the dash lights lit. The brakes would occasionally feel like they were slipping, due to the ABS kicking in. I initially thought....wheel speed sensor, since it's the same lights and same feeling in the brakes. Later that day, I went out for lunch and when I 1st started to accelerate I would hear a growl like grinding sound, then again as I was slowing down the growl was present and felt like one of my wheels was having trouble spinning, thus kind of a dragging wheel feeling. The growl got so bad, I limped into the nearest shop. Diagnosis, bad wheel unit bearing. That all happened around 110K miles and in the matter of driving about 30 miles.

The passenger side had 150K miles on it, still the factory unit bearing. I had inspected it and it looked similar to the amount of movement you had shown. Really, not much at all. I couldn't tell if the bearing was starting to fail or not since there is movement due to the tie-rod joints. It was nothing like those videos had shown. I'm not certain if it was bad or not, I just decided to replace it as precautionary maintenance. My take away is that if there really was that amount of movement as shown in the videos, then the dash lights would have already been coming on as well where I really feel it's more of an all or nothing diagnosis in that if you notice the dash lights come on that is your real indicator, Suspect a front wheel speed sensor, but you would then need to do the wheel bearing hub inspection to determine if it's really the speed sensor or the wheel bearing.

Sorry I couldn't be better help.

Some tips when you start shopping for wheel bearings. Most of the aftermarket wheel bearings such as from Dorman, Napa, Timken, and Moog come with the shorter wheel speed sensor wires which is for the 2007-2010 JK's, where you really want a wheel bearing which includes the longer speed sensor wire for 2011+ JKs for better routing and more extension of the wheel speed sensor wire....similar to your brake line hoses. The Mopar P/N of the wheel bearing which includes the longer speed sensor wire is 52060398AD or 52060398AE. The Mopar replacements in those part numbers are expensive. The best priced wheel bearing which is as good quality as the Mopar and includes the longer speed sensor wires can be found from Crown, which have the exact same part numbers as the Mopars. I purchased a Crown P/N: 52060398AD on Ebay for $85 and can confirm it has the longer speed sensor wire with the proper speed sensor routing clips. The Napa I unexpectedly had to purchase for the other side due to not being able to remove the speed sensor and the speed sensor breaking off inside the hub, cost me $140 and came with the shorter speed sensor wires, where I had to purchase the longer wire Mopar speed sensor separately for $20. When I had both the Crown and Napa wheel bearing hubs in hand at the same time, I would say the Crown seemed like the better quality part even though I paid half as much for the Crown as I did the Napa.

The longer front speed sensor wires are Mopar P/Ns 68003281AC or 68003281AD.

resharp001

Thx Rednroll. Appreciate the color. I'm going to go ahead and replace this driver's side, and test the new one with dial indicator the same way. My thoughts are kinda like this.......Traditional UB failure is probably more along the lines of what you experienced, and a lot like what I’ve read about others’ failure of grinding and such from sand/mud getting in there causing failure. I think where I’m leaning is caused more by large tires and low BS wheels causing additional strain and premature failure due to slop more than bearings hitting their lifespan due to normal wear. I’m currently 37s and 3.5” BS, but for about a year prior I was 3” BS (4.5” BS wheels + 1.5” spidertrax). I think the BS and tires combined with good bit of wheelin’ is what has taken its toll. I guess I wouldn’t consider mine a total failure per se, but maybe just bad enough to be the start of a tiny gremlin.

I can just feel something isn’t perfect up front. I am 100% certain after inspections, that my TB, DL, and TR are in good order, and I just rebuilt both BJs and they test good. The only real things left in the equation are steering box and unit bearings, and considering the difference in slop from pass to driver’s side, my money is on the driver’s UB. I had seen several posts about the differences in ABS line lengths, and also various comments about comparisons amount different brands, many along the lines of your comment in that more expensive wasn’t necessarily better. I found a Spicer unit on eBay for $89 and bought it. We’ll see. I’ll update the thread once I get it in and also report back on dial indicator result/comparison.

I can’t complain too much. Just like BJs and other things, when you choose to run mods that add additional stress, and you choose to put your vehicle in more extreme situations rather than just on pavement, this is the type of thing you should expect along the way. It’s part of the game. I wish I could say that I loved working on the jeep as much as I enjoy using it, but at least I’m capable of doing the work. I can’t imagine owning one of these things and not being able to diagnose/work on it oneself. My jeep is 5.5 years old now with ~80k miles, and has seen decent use. I've started preparing to deal with some regular maintenance these days, more so than upgrades. I had a nice couple years of no to low issues/upgrades.....I'm just moving in to the next phase I guess.

Mark Doiron

I've replaced a couple bad unit bearings. The first was because after running a quicksand filled river (very fine silt), I had ABS and ESP lights going off. Visual inspection (through the hole for the ABS sensor) revealed contamination inside of the bearing. That one was replaced a few months later by another because it started making a noticeable noise as I drove. It was obvious to me, being familiar with how the vehicle normally sounds, but probably not obvious to another person.

resharp001

Thanks Mark. I recall running across that post, and I thought it was interesting because I had never considered that in regards to water crossings. I can totally see how something like that could foul up a bearing.

resharp001

Thanks for these part numbers and specifics. My original order of a Spicer unit got refunded due to a backorder. Went ahead and ordered a Crown unit tonight. Kinda stinks to have to wait, but can't swallow paying almost $20 more to pick it up locally. Oh well, raining cats and dogs here in Texas, and no top on the jeep anyhow, so it's not going anywhere.