Humming sound when 4WD engaged?

[ScottAW]

With tonight's rain I figured I would engage the 4WD and see how it did on the slick roads. I had previously done this in my last 2 months of ownership, but all at speeds under 50 MPH on town roads. Tonight I took it out on the highway, and noticed ~ 60 and up when I put a light strain/load on the engine and drivetrain I would get a humming sound. If I gunned it I think it went away, hard to hear over the engine. But it sounds like a low frequency humming sound coming from the drivetrain.

Anyone else get this? No vibrations or other noises, seems to operate fine. But kind of a strange humming. The torsion-diff on this 4WD system is made for all conditions, not just snowy/slipper conditions, so it should be fine.

 

[zach34]

I know in my truck, you're not supposed to go over 50 mph with 4wd engaged.

 

[ScottAW]

Just to make sure you did not lock the diff did you?

I don't know how loud the humming is. I don't notice any additional noise with 4wd on.

The instructions state to change into 4wd under 60mph and keep it in a straight line until it switches (don't switch it while turning!). No speed limit while in 4wd.

I will listen for additional high speed noise next time. Realize that you are engaging the entire front drivetrain so there will be additional noise just from more moving parts.

Neah, lock was definately not engaged.

The humming is faint, turn down the radio and keep the windows closed. Could be normal sounds, just wanted to see if anyone else has heard it.

 

[EDGE]

It's normal you just noticed it cause it's still new and you recognize new sounds in new cars:

Your 04 V6 has AWD and 4WD right, so you used the AWD point where you could engage it and drive around in wet or dry road conditions, the 4WD point is not meant for high speeds above 50 or 60 mph and is meant for real slippery roads, not meant for rain but you can use it.

 

[toyo]

V6 models are 4wd not AWD, only the v8's are AWD.

 

[bluewolf]

V6 models are 4wd not AWD, only the v8's are AWD.

It's actually the same limited-slip-type system until you lock the differential. 4 wheel drive, All wheel drive, 4 full time...whatever you want to call it...it's the same result. The only difference is that you don't have the choice of putting the V8 models in 2WD.