need help diagnosing a noise

[swank501]

Let me preface this by saying I absolutely love my truck and hate to make a thread like this, but I was hoping someone here has had similar issues and I can be informed before I take it to the dealer.

2007 RCSB 4x4 5.7

When I'm slowly accelerating from about 35-45 MPH sometimes the truck starts making a somewhat droaning howl. When it starts it sounds like " waaaaaaaaaaaaaawaaaaaaaaaaaaawaaaaaaaaaaaaawaaaaaa aaaaaaawaaaaaaaaaaaaaaaaaa
" and as I acelerate it goes quicker like " waawaawaawaawaawaawaa" After 45 MPH it seems to go away. It gets on my nerves because I usually drive around town at these speeds and I can hear it over the radio. I seldom fell a very slight vibration in the truck when it happens, but it's usually just the noise. I don't think it is exhaust, it just sounds like something is out of balance

I'm not sure if this is the dreaded rumble strip issue or something entirely different, but I would appreciate any input before I hand my baby over to the dealer to pinpoint the problem

[swank501]

Originally Posted by rockstate45

Front diff. Do a search on here, print off the TSB and take it to the dealer.

Also, to make sure that's the case, put it in 4wd. If the sound goes away, there's your culprit. As you know, don't forget the rules of 4wd (Binding during turns)

-rockstate

That may be it. I read the TSB and it did say that if the noise was over 30 MPH then the TSB did not apply. I will engage 4wd and see what happens though. I do only notice the noise only after the truck has shifted into final gear. If It downshifts while I'm accelerating in the stated MPH range, the noise goes away.

[SILVER2007]

I have the same noise that you have and i have put on a resonator and a new muffler and nothing seems to help i called toyo and filed a complaint ,if you will read it is call the droan, or exhaust droan some recommend putting in a (h) pipe in front of the muffler about 14in to take care of the noise i have not done it .hope this helps