[musubi]

Aloha guys! Haven't posted in this section in a while. I've got an 06 DC Sport, AT and have been recently experiencing/noticing a low humming sound when moving. It seems to be dependent on the truck's speed i.e. as the truck's speed increases the humming get's louder and vice versa. It seems to be loudest at around 45 to 50 mph. At a stop, there is no sound. The sound is only audible inside the cabin. I had the truck do some passes to see if I could ear it outside, but I could hear nothing.

I thought it was the tires at first, but my tire tread (stock sport) is almost gone and I never had this before. I don't think it's the engine since the sound doesn't go away when placed in neutral, when moving. I shifted through all 5 auto gears and all seem normal. No other weird sounds. Just concerned here that something's wrong.

Any ideas on this are greatly apreciated. My bumper to bumper warranty is gone, but the powertrain is still intact. I haven't had the best of experiences with my local Toyota dealership here, but will go to them if nothing else.

 

[Splicer]

I thought it was the tires at first, but my tire tread (stock sport) is almost gone and I never had this before.

Tires get noisier as they wear out... the culprit may actually be your worn tires. Even though it may not be noticeable from outside the truck, there may be some odd harmonics being introduced into the body structure, making it audible from inside.

 

[TrailDust]

How often do you rotate your tires? A common cause of the type of noise you're describing comes from "cupping" when tires aren't rotated frequently enough.

 

[Dark Taco]

Rotating them might help. Those cheap Dunlops are probably at the end of their useful life anyway. Cupping of the tires could indicate bad shocks too. Take a look to see if the look like this: Tire wear

 

[musubi]

Thank you all for your thoughts on this. I've been trying to think of how to isolate this noise. I was thinking driving over grass would prove or disprove the tires, but I can't find a flat stretch of grass. I'll see if rotating the tires solves the sound. And no, the tires are not oddly worn in any way. I almost want to place the rear on stands, run it and see if the noise occurs, but that sounds like an accident waiting to happen.

 

[Dark Taco]

Thank you all for your thoughts on this. I've been trying to think of how to isolate this noise. I was thinking driving over grass would prove or disprove the tires, but I can't find a flat stretch of grass. I'll see if rotating the tires solves the sound. And no, the tires are not oddly worn in any way. I almost want to place the rear on stands, run it and see if the noise occurs, but that sounds like an accident waiting to happen.

Don't want to have this happen. :lol: Jump to 1:30

 

[TrailDust]

I'll see if rotating the tires solves the sound.

If the tires were damaged/worn due to cupping, rotation would have no effect since the damage is already done. If you're not seeing any damage associated with cupping then the issue lies elsewhere as Dark Taco suggested.

 

[musubi]

Thanks guys! That site from Dark Taco is really helpful. The hum does kinda sound like it's a "whirring" sound. This gives me a good place to start anyways. Much thanks to all. I'll keep you guys posted, for reference, on the outcome.

 

[musubi]

Update:

So, I was in the process of rotating the tires and I found the area where the sound is coming from. It's not the tires. It's the area around and between the two inner CV joints. It could be the bearings or the unit between the inner CV joints (I don't know what it's called. Looks kinda like a transfer case or something?) Anyways, the noise stems from this area and I'm taking it in tomorrow. If the problem is found somewhere along this CV axle, would this be covered under the powertrain warranty? I'm guessing not, but just feeling out people's opinion on this. The dealership will tell me if it is or not, but my trust in this dealership is just not there. The noise sounds like a whirring only when the front driver side tire is rotating.

Appreciate any thoughts on this.

 

[Dark Taco]

Sounds like your refering to your front diff. 05moose had his replaced recently this might be worth a read before you go in. Maybe he'll even chime in: Front diff vib link

 

[08TRDOFFROAD]

Yep, it definitely sounds like the front diff vib. If that is indeed what it is, it should be convered under the 5 yr/60k mile warranty.

 

[musubi]

Thanks guys for your replies. Turns out, it was the bearings causing the sound. Maybe my description of the sound was off. It was covered under warranty and now all seems to be better. I have a hard time believing the bearings went out so soon, but I'm glad it turned out to be the bearings instead of a diff or trans. The work was done fairly quickly and of course free. Thanks everyone for your help in the diagnosis.

 

[ForTech]

Wheel bearing or was it a diff bearing?

 

[bzzr2]

bump to this. what bearings? tnx.

 

[HotRod53]

I'm gonna guess here and say wheel bearing (hub assembly). I have had both of mine replaced, one around 35K, one at 98K. Symptoms are as described, diagnosis.. turn slightly right, turn slightly left, if it quiets turning right, it's the left one and vice versa. I also replaced 3 in our ZR2 trucks and one in our old Bonneville.

 

[bzzr2]

i don't think my issue is a wheel bearing, it only happens when on the gas between 62-67 or so, are you referring to a rear or front bearing? maybe i'm in the wrong thread..?

 

[PatsSfan]

Thanks guys for your replies. Turns out, it was the bearings causing the sound. Maybe my description of the sound was off. It was covered under warranty and now all seems to be better. I have a hard time believing the bearings went out so soon, but I'm glad it turned out to be the bearings instead of a diff or trans. The work was done fairly quickly and of course free. Thanks everyone for your help in the diagnosis.

I have the same situation with my 2006 DC. Except, I just installed new 5100s and new Coopers 5k mi. ago. And my gas mileage is terrible. Would the bearings cause the decrease in mileage?

I will have to take it in to have the dealer take a look. I should be ok, as I bought the 100k platinum warranty

 

[nightwatch]

I am very familiar with this sound, forget about, my dealer had everyone trying to diagnose it, factory reps his best techs, his best tech blamed it on my tires so I bought new one didn't fix it. That was after they replaced the front and rear diff, rear driveshaft, the suspension, to this day it still has a hum and it still squeaks and creaks when I turn right or left in the morning. I am trading it in. Get it documented in case something comes of it in the future.