Low Rumbling Under Throttle

[Gebo]

I had a very bad vibration on my 2005 LS430. Found out my old mechanic forgot to mark the driveshaft before removing to replace the center carrier bearing. A driveshaft shop was able to get it balanced. Replaced this newly driveshaft with new carrier bearing back on my car.

Now I just had a low rumble under throttle between 60-65 mph. Sound is similar to when you roll your back glasses down. Not nearly as loud but it is the same low buffeting rumble that you can feel. Please note. It is possible to live with.

Decided to replace the driveshaft with another one. Replaced it with a used one and the rumble is still there just like before.

My conclusion is that the rumble is not from the driveshaft of any of the driveshaft components.

Amsoil 90w-110 gear oil in rear end. Transmission fluid just changed with new Toyota WS.

What would be your next step?

I thought about road balancing the tires which only have about 2k miles on them. But the fact the noise is most pronounced under load makes me think that balancing the tires would be a waste of money. Oh, the right rear wheel bearing was replaced by
a Lexus mechanic with a OEM Lexus bearing assembly ($350). Also, the transmission mount was replaced with OEM Lexus part as well.

 

[SZR48207]

Can you better describe the rumble? Not understanding your analogy.

 

[Gebo]

Well, it is a deep bass rumble that is sorta like when you run over the rumble strips on the sides of the road. Just not nearly that loud and not nearly the vibration.

 

[Gebo]

Or to stick with my rear window analogy, it's that same rumbling sound you hear when you roll down your we're windows while driving 55 miles an hour. You know that sound that makes everybody to reach for the up button ?

 

[tiger862]

Check out the harmonic balancer

 

[mk378]

I would reach for the radio and turn up the volume.

This is why people who are into luxury cars trade them in before they get very old.

 

[PimTac]

Something loose underneath? Splash shield or other covers? Heat shields? If it's just a sound without physical vibration then that is what I would check for.

 

[Gebo]

PimTac, I can feel it. But it is not a pronounced rumble/vibration.

I was thinking the fact it only occurs between 60-65 mph and is louder under throttle would help someone pinpoint it.

 

[JLTD]

Does the gear it's in 60-65 matter?

 

[Gebo]

I'll go check.

 

[HoosierJeeper]

Kind of like a helicopter sound? had that on my Liberty, replacing the front wheel bearings fixed it.

 

[Gebo]

Originally Posted by HoosierJeeper
Kind of like a helicopter sound? had that on my Liberty, replacing the front wheel bearings fixed it.


Did it just happen at certain speeds?

 

[Gebo]

I thank all of your suggestions.

I'm gonna do some of y'all's suggested diagnosing and get back with you.

Thank you all

 

[HoosierJeeper]

Originally Posted by Gebo
Originally Posted by HoosierJeeper
Kind of like a helicopter sound? had that on my Liberty, replacing the front wheel bearings fixed it.


Did it just happen at certain speeds?


Yes. 35-40 was real bad and then once I'd hit 65-70 it'd get noticeable again. I finally figured it out as a bad wheel bearing because when I made a right turn it went away (unloaded the right front). I had other noises too, like at 25-30 there was an oscillating noise too that sounded like a mild version of a bad pinion bearing. Replaced driver's and passenger side because it has 200k on it, passenger side had noise and driver's side had play. Easy 2 hour repair! Was ready to buy a new set of tires.

 

[Gebo]

Doesn't matter if I am in 4th or 5th.

 

[JLTD]

Originally Posted by Gebo
Doesn't matter if I am in 4th or 5th.


So not transmission or torque converter/flywheel/balancer.

Ujoints are new with the new driveshaft? I'd go with wheel bearings as mentioned above. (hate to say differential, but ...differential)