2012 TRD 6 rumbling noise at 40 MPH

Many of us have heard that noise. In my case it was the drivers side half shaft at the diff.. I replaced the OE diff needle bearing with the ECGS bushing, and we were back in business.. When that was done, my shop said the same side wheel bearing was going, so they added new bearing assembly.. NOW, I'm getting the noise again but SEEMS to be from the passenger side. It seems to be most resonant at 35-40, and you can take the sting out of it by shifting to 4th on the auto trans. Noise goes away if I'm off the throttle.. And suggestions?

 

My first guess is the air intake where it goes into the fender.
Take off the air thingy bolted to the inner fender & see if it stops.

 

I'll try this fix.. TY

 

When you take it off, you'll see a shitty foam ring that goes against the fender.
Fix that & the noise should be gone.

 

I'm all about it... Thanks...

 

Any luck finding the source?

 

I did go out and check the air intake, it seems OK but I was able to manipulate the setup by grabbing it and shaking and could hear a noise that could resonate.. I didn't wrench on it, cause it's been like 10 degrees here in NH and I don't want to be out, or breaking things due to the cold.. Do you replace, or double up on the foam gasket?.. feels to me like that assembly needs to be pressing more towards the fender (in compression), but is actually just floating a little, so there is some shimmy room. Also though, I don't know what that problem sounds like. I need a gremlin to hold the intake tight to the fender while I drive. But my noise is more ballsy, and deep.. Think tires on the road, motor vibrating against the frame, etc.. My local wrench that worked on my front diff bearing, said he heard some torque convertor noise.. But most of the descriptors I've heard for that, are whiny, ringing, scraping etc.. This has more authority/horsepower.. Like a modulated moan.. Most pronounced when doing like 40 mph and the Yota shifts to OD.. Like it's bogging (which it probably is) but lf you leave it in 4th.. you don't hear it..(hardly at all) And if the noise is full on, it's then immediately off with the throttle.. I dunno if it's the TC, maybe an engine mount is smoked.. got 125K on it, but it's really clean, garaged, etc.. Just don't want thing to croak when I'm out in the deep with the sled trailer on etc.. I'm sure a long time taco wrench would ride in it for ten seconds and say "that's your ****!" But I can't pin it down myself...

 

I put thicker foam on after cleaning the flange , what you see is not the end of the air horn, it sticks thru the fender about 3-4in.

When driving about 30-35mph & the rumble starts, bump the shifter from "D" to "4" without moving your right foot to see if it stops that's how I narrowed down what made the noise.

I've had three guys inquire about having that rumble & a quick ride showed them what I was describing by doing the above.

 

Should have asked... Did you buy the foam surround as a part # or did you you hot rod it?

 

Had some left over from sealing the back door of the house.

 

Roger that...