Excessive humming while driving

[thill2]

Can anyone help me figure out why my 4Runner is so stinking loud?!? It's only when I'm moving and it's pretty much as loud at 15mph as it is at 75mph. I do notice a change in the noise when I accelerate and when I let off the gas. I can't tell exactly where it is coming from, it feels like the ENTIRE vehicle is humming. Thanks for the help.

 

[TXLUGNUT]

If you are driving with the windows down, in certain configurations, it can cause the dreaded "drone"...

 

[quicksilvr]

Probably a bad u-joint, or a bad rear differential.

 

[thill2]

No windows down

The windows are up, the u-joints look to be in good shape and I just recently replaced the gear oil in the "pumpkin". Could it be anything else? I haven't checked the Rear Diff, is there any way to check and see if that is the issue without taking it into a mechanic? Thanks

 

[quicksilvr]

The windows are up, the u-joints look to be in good shape and I just recently replaced the gear oil in the "pumpkin". Could it be anything else? I haven't checked the Rear Diff, is there any way to check and see if that is the issue without taking it into a mechanic? Thanks

What did the drain plug magnet look like on the rear diff when you changed it? Just slimy....or where there small chunks of metal in there too?

 

[durrell]

My "drone" is from a bad pinion bearing in the rear end. I'm just waiting for it to break and I'll throw in another 3rd member. Most people who have had the same issue say that rebuilding doesn't help much..the drone just comes back.

 

[thill2]

Drain plug magnet

There didn't appear to be any chunks of metal in the fluid. It was actually pretty low though. I wound up putting a lot more into it than I thought I would based on where the previous level was. The original fluid was a bit low. It has not made a difference. I replaced the tires as well, it has brand new tires and there has not been a difference as far as noise level except maybe even a bit louder now.

 

[TXLUGNUT]

turn the bass down!:moon:

 

[LINY4Runner]

Wheel bearing?

 

[core212]

i'm having the same problem. did you figure it out? it sounds like a constant hum only when driving and the speed you're going at doesn't seem to make a difference.