16' 3.5 eco. 180K!! 4x4

When I'm cruising between 60-70mph, I can feel/hear a deep rumble or vibration. But its 100% dependant on if I am using the accelerator. The exact moment I remove my foot from the pedal, it goes away and the truck glides quiet. But the slightest, absolutely slightest touch to the gas will then produce this deep hum. Pretty quiet though. I'm thinking its something right at or after the engine spinning but only makes the sound when it has power to it, such as a u-joint but not sure if that same u-joint can go quiet if no power on one end.
I can't see it being anything like a wheel bearing ect because its gone even though I'm rolling. Only present when I tough the gas just a smidge or more.

Any suggestions on how to narrow it down? There certainly isn't a way to locate where the sound is coming from. Its real deep and quiet. Just sounds like its everywhere...

 

torque converter, take it to a transmission shop they will be able to tell you with a simple test drive.

 

I'm not so sure on that. Torque converter would be RPM dependent and should do it in every gear. If it's at a specific speed it's on the output side of the transmission. Driveshafts, transfer case, differentials, wheel bearings. Might even be tires.

 

I was thinking this OR maybe even exhaust?

 

See if you can rent / borrow a set of remote microphones from a local auto parts store. It's definitely something in the driveline, since the noise only occurs when under load. If that's not an option, have a friend drive the truck while you crawl around inside, trying to figure out where it's coming from. With that many miles, it's not surprising that something may be approaching EOL.

 

.
Give this a try and see if it makes a detectable difference, then you will know.
For the cost of a spray can of Silicone liquid spray, soak the rear Cross joint on the possibility the end cap needle bearings have gone dry, rusted and binding.
If you detects definite difference, the Silicone has caused the temporary difference.
Time to have the joint replaced if yes.
I have had the experience at just 60 mph +/- 1 mph and did this to success.
Good luck.

 

I agree. I recently replaced my transmission. It was slipping regardless of which gear I was on. The torque converter was slipping and I had burned clutch rings.

 

If you have 4x4, could also be iwe noise. A slight chatter at that speed is difficult to access. If you have 4A option, turn the dial to that and give it a drive. If not, maybe unplug the solenoid by the brake booster, to keep iwe engaged. Just a cheap (free) test.

 

I have the torque convertor shudder that has started happening recently. Sounds like going over rumble strips for a few seconds under light acceleration with load on the engine like when I'm going uphill. Seems to happen more in 4th, 5th and 6th gear than it does in lower gears when I'm more into the accelerator. Doesn't happen as much in the morning when the transmission temp is cold, but when it warms up it happens almost every time.

Hopefully it's something that is covered under the 10yr/120k extended warranty I bought.

 

Been seeing a lot of posts in different places about changing the fluid and filter to correct the shudder in some instances.