2010 Toyota Tacoma TRD Pre-Runner: Low Humming Sound

I have a 2010 Toyota Tacoma TRD PreRunner 2WD with just under 24k miles. I have taken it in precisely at 5k increments for checkup, routine maintenance. Everything has been fine, but I have had the following done:

* Bilstein 5100 shocks put on (all 4) and alignment done by Toyota just 3 days later (this was about 1000 miles ago)
* TSB Rear Leaf Springs

Over the last few days I have noticed a low sounding humming noise that is actually kind to hear, but I can hear it. Today on my way home I decided to try some things out. At 60mph with cruise control set, it doesn't stop. If I start going down a slope and the gas is let off a bit, it starts to go away and everything sounds quiet and smooth. When I let off the gas, the sound starts to go away. When I put the gas on at above 55mph, I can feel/hear it. I say I can feel it, but I am not sure...the steering wheel feels like I can feel it, but this just be me THINKING I am feeling it.

I have tried to pinpoint where the sound it coming from and I know its the right side, I think the front, but I am not 100% sure.

Does anyone have any suggestions? The tires have been properly rotated every 5k miles and only have 24k miles on them. Like I said, I changed my shocks about 1000 miles ago, 3 days later getting a Toyota dealership alignment done.

I really hope I can nail this down because my TSB'ed blower motor just came in and plan to take it in for that soon, would like to get this addressed as well.

 

Anyone having the same or similar problem? Anyone suggest what the issue might be?

 

You're still under warranty and have to take it to the dealership for the blower motor TSB, let them diagnose and fix the problem.

 

But what do you think it is? I can't just go in to a dealership without a plan...you know that...

 

Here is what I am thinking. I think it may be the u-joints and was caused by an out of angle driveshaft since having the TSB leaf springs and the Bilstein 5100's installed.

Do I need to have the driveshaft angle gauged?

Does my theory hold?

 

Took to the dealership and they said nothing was wrong with the drive train (not sure they checked anything - wheel bearings, ujoints, pinion bearing....etc). The tech tried to show me "slight" wear on one of the tires on the rear, but I have my tires rotated every 5k miles. Again, I only have 24k miles on these tires and have never abused them. He claims this is "road noise", but road noise would do it constantly and would NOT give me vibration in the steering wheel and pedals (as slight as it might be).

I do NOT think its the tires because it only happens at a certain speed and above, and seems to go away as soon as I (or cruise control) let off the gas.

What I did notice today while looking closely at the tires was cracking within the grooves of the tires. These are the BFG Rugged Trail T/A's and have been great tires thus far. Is there ANY chance my 100k mile warranty I purchased get me a different set of tires (even with me below my original 36k mile warranty)?

The noise is there....and I don't know how to handle this anymore. Suggestions?

 

People have had problems with their windsheilds not being perfectly sealed, perhaps that could cause a humming/airflow sort of sound?

Just throwing ideas out there.

 

Not even close. Again....it happens at 40mph and above...and goes away as SOON as I or the cruise control lets off the gas.

 

That does sound like a drive train noise.

If it started happening after the 5100's I would consider the driveshaft. Maybe there is just a slight vibration being set up in it. Do some searching around here. There are lots of different tricks people have come up with to resolve this.

In my experience noise like that has either been the rear diff, or u-joints... But that wasn't on tacos.

 

Tricks? I am not good with doing anything with the driveshaft (I have read turning the drive shaft around helps. Shouldn't the dealership fix this?

 

I doubt it. How much lift do you have? From what I understand the problems usually start around 3in or higher.

check this out

http://www.tacomaworld.com/forum/2nd-gen-tacomas/153050-just-fixed-driveline-vibration-free.html

He's kinda hard to understand, but I think he fixed it pretty much with shims under the leaf pack.

If you determine thats the problem (or worth trying), I'm sure you could get a shop to put them in. I wouldn't think they would charge much more than a hour to do it.

 

I am still under warranty though. Why can't I get Toyota to diagnose and fix it? I have no clue how to work on the underside of my truck.

 

Odds are, they will just say that the lift is the cause of the problem, and if you want the problem gone, remove the lift.

Its hard to say exactly where the problem is though. One option could be just to ride on it for a while and see if it gets worse.

In the event whatever it is, is causing damage, I would be sure to put a lot of energy into fixing it before your warranty expires though (if it hasn't gotten so bad its easy to pinpoint by then).

Just keep researching and learning here on TW. There is a lot of knowledge and experience scattered throughout all the BS on this site.

Keep learning and before to long you'll be like some guys that refuse to even let a dealer touch their truck.

Two words of advice,

One: don't just throw money at a problem. Research and research.

Two: As much smack as people talk about dealerships, don't let anyone but a dealer and yourself touch your truck. You have no idea how much dealers make by fixing independent shops screw-ups.



You might get the dealer to inspect your rear diff for water and or metal shavings though. I had a diff burn out on my once (bad gear oil) that had very similar symptoms. That would probably be covered under warranty without much hassle.

 

Technically I didn't lift anything.

 

Anyone have any other ideas?

 

Start simple and grease the u-bolts. Chances are they haven't been greased in a while or have not been greased at all. Are all your tires balanced properly, tire pressures correct side to side, etc. Also, there are weights on the rear hubs. I'm not sure if they'd cause the vibration you're talking about but mine fell out when I did my lift so maybe they did on yours also? They're stuck on the brake drum assembly (surface mounted to the outside). There were 2 of them on mine and both are gone.

Also, you asked about tires a little further up... I wouldn't attempted to get tires covered under warranty, they're considered a consumable item.

 

I think the tires out of balances. Did your steering wheel shaking when you go above 60mph?