Mystery noise: cyclical humming from front right side (1 Viewer)

[rocketman999]

New to the 100 series party! 2001 LX470 155K miles.

I have done some baselining: oil, diff and xfer case fluids, along with filters, etc. Most recently I have deleted the AHC and installed a Ironman Nitro Lift kit with diff drop. I also pumped grease into the slip yokes and 2 of 4 spider yokes (had trouble with the zerks, the gun wont fit on one, and another had the wrench flats rounded off, gonna figure something out eventually)

Now I'm hearing a humming sound that is cyclical in nature: "hmm hmm hmm hmm hmm" for example, about twice per second at ~20 mph, and it does increase in frequency as speed increases. Pretty sure this was always there, but it seems louder now, probably because other things have quieted down or I'm becoming more sensitive to it.

I feel like its coming from the front right wheel, but I'm just guessing. Does this seem like a dying wheel bearing?

 

[KosPar]

At those speeds, if it happens immediately after you brake, it could be the brake fluid reservoir, but that's right behind the steering wheel in the engine bay.

 

[yngmrostrvile]

Your LX is mad you delted the AHC.
Does the noise change if you change the weight distribution side to side of the vehicle going down the road? Try, safely, steering 11 to 1 to see if the noise changes. That would be an indication of a wheel bearing. Have you lifted the front and checked to see if one of the wheels is "loose"?
Try the hydraulic brake system and then emergency brake to slow the vehicle to find out if noice changes.
Hows the tread of tires?

 

[rocketman999]

AHC had leaking shocks and wouldn’t go all the way up to H then error out. If no leaks I wouldn’t spent more time. The PO was a service adviser at Lexus and if he didn’t fix it with his resources then it’s pretty telling it’s dead.

Braking doesn’t increase the sound. Maybe even reduces it. Coasting maybe reduces the volume slightly but not much.

No play in the suspect wheel when in the air.

The noise does change slightly when shifting weight around (bumpy/curvy road).

Tires are newish and not aggressive at all. At 70+ mph it’s sounds like I have one crappy M/T tire with a smooth hum.

 

[ramangain]

Good time as any for the wheel bearing service. You get to reassemble the brakes anyways, so check for missing or worn parts.

Become ONE with the grease .....

 

[gatormark91]

Check that the diff has gear oil in it. It's closer to the right front than the left. Check the bearings, too, that is the likeliest culprit, IMHO.

 

[lehiguy]

If you just installed a lift, chances are you are experiencing some driveline vibration from the rear. As you lift these, the rear pinion angle turns upward a little and it doesn't agree with the angle of the flange on the T-case. This can cause vibrations, especially if the slip yoke has a little play.

 

[rocketman999]

I finally got all the parts and tools in and went and replaced the bearings on the front right wheel. The old ones looked fine but I already had the new ones so I decided to just swap them out. After going for a test drive, the noise was still there, but sounded more like it was coming from the left wheel now.

Got home, jacked up the front and got 12 and 6 o'clock wobble from the front left. FML.
Pulled the dust cap, clip and front hub flange off and the lock nuts were loose. The bearings are TOAST--heavily pitted and metal particles everywhere.

Now for the million dollar question: Do I wait several days for new Koyo or Timken bearings, go with new "Duralast" today from autozone, or rebuild using the old bearings from the right side? At least the outer race looks good (haven't pulled whole hub off yet) so slightly less work if I were to pop in the old bearings.

 

[Asanka]

Patience, get it done right. You'll be good for 200k+ with proper maintenance then

 

[rocketman999]

Got a Timken set on the way. I was frustrated--logic won out eventually! Hopefully this solves the problem but there's certainly no chance it doesn't help given the state of the bearing.

 

[rocketman999]

Late update, but I think its worth mentioning that the new wheel bearing solved my problem. I would've saved myself some time/effort if I had inspected both before replacing.

I've learned its pretty hard to tell where a sound is coming from. Definitely inspect both wheel bearings to be safe.

 

[Joshuak172]

Late update, but I think its worth mentioning that the new wheel bearing solved my problem. I would've saved myself some time/effort if I had inspected both before replacing.

I've learned its pretty hard to tell where a sound is coming from. Definitely inspect both wheel bearings to be safe.

This sounds very similar to a sound/vibration I am having from the front end. It sounds like a “wub wub wub” that increases in frequency with speed. Took it in and supposedly had the front bearings serviced back in January but the noise persists. Might have to get in there myself considering the luck you had...