Humming/buzzing sound at certain speeds

[seadragon]

Hi guys,

I am hoping to run a scenario by you and see what your thoughts are regarding a minor but rather annoying problem. Sorry if this is a bit long, but perhaps someone that is also experiencing this may be able to do the same tests I did.

A few months ago, I started noticing a humming sound/buzzing sensation at certain speeds. At 40 KPH, I can hear a "wu wu wu wu" sound and feel it in the steering wheel and floor. At highway speed, it feels like a constant buzz (similar to holding an electric shaver). The problem started back in around August, 4 months into owning the truck.

I took it for a test drive with a tech and he was able to feel a bit of what I was talking about, but for some reason, that day it wasn't as noticeable. They rotated my tires front to back and it made no difference. The next thing they want to do is swap my wheels/tires with another Tundra to see if that works (next Saturday).

I've suspected however that the tires are not the problem since it doesn't seem to matter what kind of road I'm driving on etc.

So, today I found a nice long stretch of a paved, deserted road and did some more testing on my own. Here's what I discovered:

- at 40 KPH, "wu wu wu wu" sound and buzzing felt in steering wheel and floor
- engaged 4WD and the sound/buzzing stopped!
- went back to 2WD, and the sound/buzz came back
- 4WD again, and it stopped
- 2WD again and it was gone!

I went back in and out of 4WD a few times and discovered that the sound only occurs in 2WD and is hit and miss after coming out of 4WD.

So, I thought the front drive shaft may be resting in a certain spot that causes vibration. I got it in 2WD where the vibration was gone and I manually turned the driveshaft a quarter of a turn and drove at 40 KPH. I did this several times and the sound did not come back. I then engaged 4WD for a minute and went back to 2WD and the sound was there again. I rotated the front driveshaft again by hand and drove, the sound was still there. So the position of the driveshaft has nothing to do with it.

SO...

It would appear that the sound is a vibration from a rotating "part" that comes to rest in 2WD. The vibration depends on the position of said "part" when it comes out of 4WD. When the sound is present, the "wu wu wu wu" is tied to the rate the wheels are turning.

I hope this makes sense and would really appreciate anyone's thoughts on what it might be. I don't know a lot about the guts of the 4WD system, but I do think it has something to do with it. At this point, I highly doubt the tires or alignment would be the cause.

I'm still going to have the dealer swap the wheels to see what happens. I want to give them as much info as possible, but I have a bad feeling this may be a hard one to pin down.

Thanks for reading! Does this make any sense?

[Impelled]

Could it be some variation of the "rumble strip" transmissions that have been documented?

[seadragon]

Originally Posted by Impelled

Could it be some variation of the "rumble strip" transmissions that have been documented?

Thanks Impelled. The thought did cross my mind, but I ruled it out. The sound has no relation at all to what gear I'm in or if the tranny is shifting or if I'm accelerating, coasting or braking etc. My tranny has been working flawlessly actually. The best way to describe it is like if you throw your blackberry or treo in the cup holder and it starts vibrating (not a call ) and you reposition it and it stops. Only this is something under the floor of the truck doing it. It might be as simple as a heat shield resonating or maybe something to do with the front hub assembly.

[hit_em]

I get a buzzing sound but I get it going about 140 KPH. and you cant feel it in the steering wheel. mine sounds like it comes from the wipers.

[ksmith19]

I am experiencing something similar at about the same speeds that you are. The only difference is I don't hear any odd noise. I just feel the vibration in the gas pedal/steering column. It does seem to come and go though. I have not tested it on pavement with 4W but will do so to see what happens.

[VonBarrett]

Lemon?????

[jclark408]

my 07 cm trd 4x4 does it too....DRIVES ME CRAZY........beginning to regret this thing after selling my Titan..........I have teh rumble strip problem........Dealer has no clue that it exists (looks like I have a great chance at them replacing my torque converter).......RIDE IS HORRIFIC.......I'm very detailed about my ride and the bugs in this thing are going to drive me insane

[4REF1FAN]

Could it be the torque converter???

[seadragon]

Originally Posted by 4REF1FAN

Could it be the torque converter???

No, it's definitely not the TC. The sound at 40 KPH is rhythmic and is tied to the speed the tires are rotating. I think it might be something touching the front diff that is transmitting the vibration into the floor perhaps.

I'm taking it in tomorrow morning to the dealer for a further look.

[seadragon]

Hey guys,

Just a quick update for you. I took the truck into the service department today and they swapped my wheels for 20" Bridgestones from a '08 Limited Tundra. Took it for a test drive and it made no difference. Same noise and vibration.

So the wheels and tires are officially ruled out of the equation.

The tech that was with me thinks it might be a bad bearing. They're going to order up a bearing to get it in stock. Then I will drop my truck off for the day with them and they will do further testing. If a bearing is indeed bad, they will have the replacement ready to go.

But, the fact that the noise is very subdued in 4WD has me concerned in that I believe a bad bearing would cause noise all the time.

In the end, my dealer is doing a good job and I'm confident they will find the problem. It's taking time, but I'm a very patient guy as long as I know they will work on it until its fixed. It appears that is what they intend to do.

[4REF1FAN]

^glad to hear. Sounds like they are willing to fix the problem.

[seadragon]

Just another update on this problem...

Truck was at the dealer all day today. They replaced the passenger side wheel bearing but it didn't make a difference. I don't know how they decided it was the passenger side bearing that needed replacing. I didn't think it was a bearing from the beginning, but what do I know?

So, now the truck is going in again on January 2nd and they are going to use "electronic ears". A magnetic microphone that they can attach to almost anything under the truck and listen with headphones. They will be looking/listening closely to the front differential. I have a feeling the diff is the problem. If it is, it will be replaced. I'm determined to get this resolved, even if it means replacing the whole driveline.

[PappyTRD]

I'm having the same problem. The noise does go away while in 4wd and I noticed that the sound goes away only if when I cycle back to 2wd and I get a heavy "thud" from the front end.

I'm wondering if the front lockers are not properly lubed and they are not disengaging properly?

Any thoughts? I'm heading to the dealer on Friday...will keep you posted.

[guapo]

When you are shifting from 4wd to 2wd you are changing the amount of load that the differentials are having placed on them. I would beleive that if there is as way to jack up and truck and place in it gear then that might work to find out what the problem is. They can then look. If the front drive shaft is not ballanced or it could cause this problem. Or if the drive line is out of line/balance this would cause this as well. One way we checked was to place the vehicle on 4 jack stands and loosed up the center bearings and place in drive and let it run and then retighted everything up. To me it seems to be in the drive line. Since it is 4wd did it start after a 4 wheeling trip. IMO Good luck

[PappyTRD]

It started after using it on a drive to work in heavy snow. For me, it is prominent that it is comming from the front left wheel. I will mention this to the dealer when I head in.