Hi,
after driving BMWs for couple of years decided get back to the LS family. Got myself a 2007 LS460 with 50k miles on the clock. So far have done front rotors and pads. Now my first problem arrived:
I have noticed a high pitch noise from the drivers side starting from around 40mph. I had a bearing go out on my previous LS430 and I think this noise is somewhat different. It is not constant whawhawha-type that a bust bearing usually does. It also varies between surfaces that I drive on so on rough road it is more prominent. The car came with extra set of wheels and I changed those today and the noise is still there (Btw I was surprised to find out that 20" wheels with Goodyear Eagle F1:s give less road noise than the 19" F-sport wheels with Continental Contisportcontacts).

Any ideas how to go forward with the diagnostics ? Changing the wheel hub seems like a pretty easy DIY but wanted to make sure I am on the right track here. I can't think of anything else than the bust bearing since the noise is more prominent the faster I drive. On the other hand if it is the bearing it should become worse over time ?

Would appreciate any input. Did do the searches beforehand.

BR

 

I've never heard a bearing give a high pitched noise before, you said you just had your brakes done, any chance it's a backing plate or a piece of brake hardware rubbing against the rotor?

But you never know, it could be the bearing, but I've never heard one have a high pitch to it when it fails.

You could try removing the brakes and turning the bearing by hand to see if it feels rough. My bearing went bad on the passenger side and when I went to change it I turned it by hand and sure enough it felt rough.

 

Check the caliper on that side to make sure its not sticking. I had a "whawhawha" on my RX I thought was a bearing and it was a stuck caliper.

 

This is what a bearing sounds like in my thread...

https://www.clublexus.com/forums/ls-...his-sound.html

At least what the noise sounded like while driving at 65-70mph...

 

Thanks for the link DavidinCT, the sound is different from that. And I do remember this was what I got on the LS430 with the bad bearing. On the LS460 the sound is probably best described as the road noise being more apparent from the front left corner. I did check the caliper since I did the breaks but that seems fine. Pad wear is even and the car is not pulling to any direction.

Are worn control arm bushings know to cause something like this ?

Thanks again for any input

 

I have now ruled out a stuck caliper: I did disassemble the pads and shims and did not find anything pointing to stuck break issues. While in there I did check the front left corner for any signs of bad bearing: no play or groaning sounds.

I am still a bit confused what could cause this ? One possibility would be early stages of the bearing going. I do not have any signs of the control arm bushings: no handling issues, no squals or clicks going over bumps. I would not want to replace the hub if I am not 100% sure it is the bearing itself. The sound is still there, kind of prominent road/tire noise from the front passenger side and it gets worse around 70mph.

Any suggestions ?

 

Wheel bearings can make different sounds when they fail. Some make a wuhwuhwuh noise like an old-school snow tire. Others make a low-pitch hollow noise. My LF wheel makes a really odd resonant noise at about 76MPH, like a ringing or howling. Every bump I hit makes a noise with the same resonant frequency. I replaced the tires and it now makes the same resonant noise, but at 45MPH - maybe a function of the tread block count of the new tires vs. old....Hopefully not the air strut!

Often there is no play in the bearing, or even evidence of roughness, grinding or noise when the wheel is spun while the car is on jackstands. Such is the odd failure mode of sealed cartridge-type wheel bearings.