kanda

I often read this forum when I have problems or questions about my 2004 GX but am not a regular contributor, but I thought that my recent experience might help a few folks.
sorry, it is a long post and no pics

I have a 2004 GX with 191K on the clock. I have had it since it had about 60K and for the most part, have had few to no issues with anything. With regular maintenance and inspections, this car will run forever I have decided.
I do almost all my own service and repair except for when time is pressing and given that I live in an area without a Lexus dealership, and no mechanic that I love and trust, I have taken it to the local Toyota dealership a few times for things that I don't have time for.
About 6 months ago, I finally had a couple of my original equipment front axle CV boots break down and tear and leak a bit of grease and didn't have time to do the swap, so I bought a set of new aftermarket axles and had them installed at Toyota. No problems there and I was on my way, several hundred dollars poorer of course.

About 2 months ago, I had the tell tale rumbling of a wheel bearing going bad. Sounded like I was running aggressive tread tires with an increase in noise with increase in speed regardless of transmission position (drive or neutral), transfer case (high or low or neutral) position, or anything else. The noise became less when banking or turning right, and taking the weight off the right side of the truck. On an on- or off-ramp from the freeway, the noise would basically disappear with right turns, and increase with left turns. No change in sound with engine loading, so likely not the differential. Some vibration noted in the steering wheel at speed, but mostly just a noise like the hummmmm of tires. Hmmmmmmmmmmmmmmmmmmm.
Ah ha!! it must be a right sided wheel bearing. The front always goes out first, so that's what I suspected.
I jacked it up, put it on stands, and wiggled the front wheels. No play whatsoever in any direction even with heavy manhandling of the tires. No suspension looseness, no changes or sounds with rotating the wheels in neutral, no grinding with manual rotation of the front wheels, no difference in force required to manually rotate, etc. Did the same for the rears and no play or problems. both sides the same left, right and front and back.
Well, it must be the right front bearing by symptoms, so I bought a good quality aftermarket hub and bearing kit and pulled the hub from the right front of the truck and installed the new one. this is not a hard job, but it is a press-in hub/bearing assembly, so do not attempt if you don't have, or have access to, a good shop press.

I put her all back together and took her for a test drive and goddamn it if the noise was still there. I figured I got a bad bearing or screwed up the press process or something. Same sounds and symptoms, goes away with right turn, and a bit louder with left turn.
Tires were nearly new and all fine except for slight feathering on the right front tire, barely perceptable on inspection and by feel, insignificant in my opinion.
I rotated the tires and checked the alignment, all was nearly perfect. Still the noise.
Then my feeble brain decided that the noise was more in the back on the right since that was the side that the noise disappeared from when turning right and taking the pressure off the right side.
So I pulled the right rear axle and the bearing had a little resistance to turning but not bad, so I replaced it. That is a harder job than the front and the pressing process requires a long adapter that I did not have or wanted to make for my press, so my local machine shop happily pressed off the rear axle bearing and I re-installed the axle.....
Yup, you guessed it, noise still there. Damn it!
I then ordered a new front bearing and hub set from bluepitbearings.com. These guys do quality work in my opinion and the bearing / hub assembly was quickly shipped, well packed and with OEM parts, Koyo bearing, etc. Maybe a little more money than the local autoparts store, but the thing is a bolt on assembly and I opted to try that in case my pressing skills were at fault with the initial attempt.
I drove it around for a week and cussed the fact that I had to redo the right front bearing and considered that maybe my nearly 200K truck that I love needed to be replaced, I even looked at new GX's and drove LX570's and an assortment of other things and decided that I could not bear to part with more than 30-60 thousand bucks or more at this point because of a stupid grinding/ tire noise in my truck. Of note, I did do the 90K service with timing belt, pump, all pulleys, new radiator, etc about a week before, so I'm now committed to keeping her a bit.

After considerable mental deliberations, I took the right sided bearing/hub assembly back off and replaced with with the bluepit hub assembly and removed my newly rebuilt hub, which looked fine of course after only a hundred or so miles of use. Yup, noise still there. MotherF****r.............
Now is the time that I begin to mentally panic and question my mechanical skills. I can fix most anything but this is driving me crazy. I pulled the TSB's on noises and read them all. Inspected everything, read every post on every message board that was related, talked to the toyota techs, who basically could not get my truck in at any reasonable time and offered an expensive array of "diagnostics" and finally decided to place my newly rebuilt hub assembly from the right front on the left wheel just in case that was the issue. They are reversible and universal and it was sitting there in perfect condition on the bench looking at me.

After removing the wheel and axlenut and disc and caliper from the left front and pulling the left front hub assembly the problem was clear.

The inner of the paired left front bearings in the hub assembly was clearly bad and had some resistance to manual rotation The outer was totally fine however, and thus no play in the wheel and when turning right, when the weight of the vehicle would be all on the outer left front bearing and off of the inner somewhat to make the noise disappear. this mimicked the right front bearing going bad, but in fact it was the inner left only.
There, also, inside the spindle assembly hub housing were the remnants of a thin spring that goes circumfrentially around the CV joint oil seal.
Remember the beginning of this story?
The inner spindle-hub-CV oil seal was new and intact though, no pieces of spring missing from it.

Well, best I can tell, when they swapped out my axles at Toyota, they damaged the inner seal on the spindle and replaced it as this was a new inner seal that I was staring at. In the process, they left the spring, or pieces thereof inside the bearing housing which subsequently got ground up and ate the race and rollers from the inner bearing causing it to fail. There was no water or rust or anything else in there that could have indicated alternate causes to the inner bearing failure.
So...
Lessons from this saga:
---Dont trust anyone to help you work on your car if you can avoid it even if they are the dealer, factory trained, or whatever.
---Traditional wheel bearing diagnostic symptoms may not apply in applications such as the GX with paired tapered roller bearing assemblies, as failure of the inner bearing on one side will mimmick symptoms of the other side going bad.
---Always replace bearings in pairs if they have the same usage time on them (same goes for headlights, tires and other assorted paired systems).

Sorry for the long post. I hope this helps someone out someday. I sure have had some help from posts on this board and others. Great community!

chiph9

Wow, glad you were able to find that.

Chip H.

IanB2

That would be a frustrating diagnoses for sure, good work!

LoneHiker

I didn't know these bearings could fail in that way. I replaced my left bearing a while ago for same reasons as you, and it didn't make a difference. Now I know it's time to check the right one.

EddieK05

Thanks for the info. I'm about to replace both fronts whenever they finally get here. Just have a slight vibration at about 50mph and a little noise. Just a word of note, if you order from marionb2b who has been recommended on here, his communication is terrible. Have sent him 2 e-mails and tried calling him, no response, placed my order 9/23.

LokiGx

This might be an exact situation I'm in right now. On my 11 GX460 with ~120K miles, I started getting the humming noise from the front which goes away if I make sharp right turns indicating the passenger front has the bad bearing. I went ahead and bought a dorman hub assembly with the bearing and replaced the passenger front hub, it was a PITA to get the old hub out. Was happy to get eerything in and went for a test drive and damn still same sound which goes away on sharp right turns. Then I made someone else to drive and sat on the rear to observe if any noise was coming from the rear and there isn't any. So it much be the front one which I already replaced.

After looking at this post, I doubt may be the inner bearing on the driver front side is causing the noise. will order a new hub assembly and do the driver front too and hope it goes away.

Lexus4321

What type of humming noise? Can you describe loudness (like barely heard, or obvious), and what freq (low, mid, high pitch)?

You took the hub off, why not replace the CV shaft while in there, they are not that much $$.

Are the CV shaft boots ripped at all? My driver side boot got a rip at 185kmi, replaced it, then replaced passenger side at 191kmi. I will keep the OEM shafts to be rebuilt.

At 224kmi now, I have a small leak from rack-pinion unit, will need to replace that soon.

LokiGx

Its a very low pitch humming start to get audible at around 30-35mph. I checked the CV shafts , the boots are intact and no loss of grease around them.

I'm wondering if the humming could be due a bad tire. I recently purchased this GX used and noticed that the front driver side tire has 9/32" tire depth whereas the passenger side has 6/32" tire depth, will try to swap the wheels from left to right and see if the humming has transferred on the opposite side. The previous owner said he had got new tires at 86K miles and after 10K miles one of them got a flat and the lexus dealer recommended to just replace the damaged tire since the other ones are nearly new.

Lexus4321

Have a Discount Tire or the like do a road force spin of your front tires. That will tell you if you have a bad tire.

I had the DT Cooper tires, and when the tread got low they started to "hum". I now run Nankang SP9's.

LokiGx

Oh Boy! it was the driver front wheel bearing which was bad!!! Damn that's so opposite to the usual diagnosis which points to a bad bearing becoming noisier when turning the opposite side. Immediately after removing the wheel bearing, was able to hear the little rough rumbling noise when hand rotating it.

After the failed attempt of replacing the passenger front bearing, just to make sure its not the tire noise I rotated my tires and still had the same humming noise which would go away when making a sharp right turn, so ruled out the tires and got a new bearing hub assembly and replaced the driver front side and voila it worked. No more humming noise and its buttery smooth

Very thankful to this post, without it I would have gone mad trying to figure out what's causing the issue or end up going to a Lexus stealership making me lighter by couple grand

I couldn't find any relevant post on the 460 forum, I will probably post my experience there too, should be helpful to someone.

LokiGx

Oh Boy! it was the driver front wheel bearing which was bad!!! Damn that's so opposite to the usual diagnosis which points to a bad bearing becoming noisier when turning the opposite side. Immediately after removing the wheel bearing, was able to hear the little rough rumbling noise when hand rotating it.

After the failed attempt of replacing the passenger front bearing, just to make sure its not the tire noise I rotated my tires and still had the same humming noise which would go away when making a sharp right turn, so ruled out the tires and got a new bearing hub assembly and replaced the driver front side and voila it worked. No more humming noise and its buttery smooth

Very thankful to this post, without it I would have gone mad trying to figure out what's causing the issue or end up going to a Lexus stealership making me lighter by couple grand

I couldn't find any relevant post on the 460 forum, I will probably post my experience there too, should be helpful to someone.

Lexus4321

So you bought a whole new hub?
Can't a new bearing be pressed into the existing hub?

LokiGx

Yep, got the whole new hub, easy to replace and its not that expensive. I don't have any tools or apparatus to press out old bearings and press in new ones. Having a hub, being a novice in wrenching things, I was able to swap out the hub assembly in 2hrs.

Kandabear

So glad the thread helped you! I saw it pop up and remembered writing it 4 years ago (under my old user name). It was a difficult diagnosis for me as well!

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