filmteknik

RX350 2008 - About to hit 80K miles.

Within the last week or two I've noticed a sort of hum / vibration when I get above about 40 or 50 mph. It's very subtle but I don't think it was there before. The best way I could describe it is like what you hear and feel when driving on grooved pavement which is actually what I thought at first.

The pitch varies with the road speed and is not related to engine speed at all (it doesn't change if I shift to neutral and let the engine drop to idle). Stepping on the brake does not affect it other than if I slow the vehicle down. I have about 20K miles on Bridgestone Dueler Alenza tires; I don't know if they get noisier over time. I rotated them over the weekend but did not notice anything out of the ordinary.

Driving over rougher pavement masks it and I could be imagining this but I thought maybe the road noise then had increased so one possibility was a loss of some sound deadening.

I don't want to take it in for service if there is nothing wrong (I've been doing the basics myself) but I don't want to find out too late that that vibration meant a differential or something about to fail.

Any ideas?

I was thinking about trying to record the sound and measure the frequency because that way I could calculate that it's the same as the rotational speed of the tires or a drive shaft or something like that. For now I will guess maybe 150 Hz at 50 mph but I could be completely wrong.

RX330inFL

Two ideas:

Tires. Be sure to not only have them rotated from front to back, but you also need to cross the set going to the drive wheels. The Alenzas are said to not be the quietest of the tires. Mine are perhaps a little louder than when new, though I have no complaints. Here is something for your review on tire rotations and noise from Motorweek:

http://www.motorweek.org/features/go.../tire_rotation

Wheel Bearings. Could be first indications your wheel bearings are starting to go bad. Do you have an AWD RX? This seems to be a weak spot.

Neither problem requires immediate attention. Keep an eye on the problem and see how things go. Perhaps after a proper tire rotation things will get better.

daryll40

I had that earlier this summer and it turned out to be wheel bearings. Which Lexus covered under my CPO extended warranty, but I've heard that they'll cover it as sort of a secret warranty....maybe, even if you don't have an extended or CPO warranty.

filmteknik

Wow...if it is wheel bearings (and from poking around it seems like this is an issue on this vehicle) it sure doesn't speak highly of Lexus design engineering. I've never had them go bad on a prior vehicle by double the mileage. That would stop me dead in my tracks from buying another. Maybe they have addressed this issue by now (one would hope so) and every car is going have something that needs improving I suppose but this is something so basic.

Steve

rcy

I concur with the others...possibly a wheel bearing.

If a bad wheel bearing is going to stop you 'dead in your tracks' from buying a Lexus, I guess you'll be walking or taking public transit everywhere, because I can't think of any other manufacturer that doesn't have problems with their vehicles, be it wheel bearings (minor in my opinion) or other things. Think of Acura/Honda with their transmission problems, Nissan with their engine problems (ingesting a loose bolt from the throttle body)/bad coils, VW - everything electrical (especially coils), GM vehicles with the DI (direct injection) problems, etc. etc. etc.

MerlinT

Bearing: happened to me last month!

daryll40

RCY is right. A bad wheel bearing is a PITA, but it is a wear and tear part and even Lexi aren't totally perfect. But it's not like the engine dying at 30,000 miles or something. Fix it and move on.

hypervish

Yo do realize that your driving habits are directly related to the life of the wheel bearings. The faster and sharper turns that you make, the lower the life of the wheel bearing. Take turns slower and your wheel bearings will generally last longer.

I have almost 190k miles on my original wheel bearings all around. If I had to wake up tomorrow and replace them, I wouldn't mind because it's better than messing around with electrical issues (i.e. german cars), or replacing a head gasket, rebuilding an engine, or even worse a transmission from one of the wonderful big 3 domestics, the list can go on forever.

filmteknik

I realize there is no way for anyone to know without driving it but is it more likely a front wheel and is there some way to easily tell?

Should both (both front or both rear) be done at the same time and is there any savings to doing so? Or just wait til the next one goes?

Is this a repair where going to a Toyota dealer can save big money while still having (sorta) factory expertise? Or is this something any decent shop can do? Like nothing weird that they would not be familiar with.

Thanks for everyone's advice.

Steve

RX330inFL

While under warranty you would likely to have only the bad one replaced, I was always taught to replace these in pairs for that axle.

This is a fairly easy repair. Any shop can perform. However, you will not be purchasing just the wheel bearing. Rather, you will be purchasing a new wheel hub for each corner with a new bearing already pressed in.

thomas1

The front hubs dont come with bearing....Only the Rears....The front bearing is in the steering knuckle which has to be removed. then the bearing is pressed out...

Paul1307

You mentioned rotating tires: do your tires have anything on the sidewall like an arrow going around the tire and a logo that says "tire rotation?" Not all tires are made to rotate in both directions, particularly tires that are best for wet weather. Check this

filmteknik

Nah, nothing like that on Dueler Alenzas. I just did the rotation after this noise thing started so I am inclined to believe that folks are right about a bearing going. This in fact was the first rotation on these tires and I just did front / back as I always have done with radials and did with the OEM Michelins. I do not rotate too often because I notice very little difference in wear between positions.

The manual says the rotation should include the spare (into the rotation on one side only) but I have avoided that because that would make the wear unequal from side to side. If it's correct that they are now saying one can switch sides that would change things. Not with the current tires though because the spare is still the Michelin. Maybe I will go back to the Michelin Energy tires next time and if they are still making the same model just buy three and use the spare and put a by-then worn out Bridgestone into the spare position. Of course then there'd be the issue of the spare having aged even if never used.

But I digress.

To those who have said I should just be glad a bad axle bearing is not a blown engine or trans, yeah sure. I'd be very ticked off if I had such a failure. But that doesn't mean I'm not disappointed that a car that should have better reliability has something fail that on others has lasted the life of the vehicle. And not just some bad luck semi-random failure but something that I'm being told is common. And three left to go.

So how much of a ding is this gonna be at a Lexus dealer? How much elsewhere?

filmteknik

How does one know which one it is? I just tried jacking all 4 wheels (one at a time) with the trans in neutral and parking brake off (other wheels well-chocked), and turning them to feel for any play or difference in roughness but I could not notice any difference. Maybe this is still too early in the bearing failure. If that's what it is but it's as good a theory as any.

Carver

Have you checked the tires for cupping? The sound cupped tires make is exactly like a wheel bearing. Early cupping might escape visual detection but can be felt by running your hand across the tread surface toward the edge.