Unidentifiable noise

I noticed a loud "womping" noise, sounds almost like driving on a flat, about two weeks ago.
The next day I loaded my bed with a few hundred pounds and moved 650 miles and never heard the noise at all. Since moving I've only driven my Tacoma about 10 miles (empty) and the noise has been loud and clear for all ten.

i can't identify where the noise is coming from. Fluids are all good. Tires are good and fully inflated. While driving the pickup I cannot feel anything through the steering wheel, pedals, or stick.
Since I bought the pickup 3 years and 30k miles ago it has always had this pretty odd whine seemingly coming from the rear end somewhere, makes me think the issues are related.

Here's a video a took and posted on YouTube. For some reason my squeaky clutch that is normally barely audible is amplified to deafeningly loud, and the super loud noise seems pretty quite.

https://youtu.be/wQ7Xj9IoTOg

Happy thanksgiving y'all

 

Slide underneath your truck and grab the driveshaft and see if it has a bunch of play. Sounds like a blown carrier bearing to me. It's responsible for keeping your driveshaft smooth at speeds. Is there any vibration with the noise ?

 

wheel bearings will make a noise but you should be able to identify which wheel

 

Thanks for the responses. Drive shafts (4x4) are solid. I tried pushing them front to rear, and side to side. Checked them in a parking lot so the pickup was in first gear. Should I chock it and check in neutral?
Surely it isn't just that the zerks need a pump of fresh grease...? But I'll do that too and see.

Wheel bearings is a good thought. I'll jack it up and take off the tires and check. If the seals are good the bearings should be good? Or if I spin the tire won't I hear a clicking sound?

I drove it a few miles today and for the first time could feel some vibration through the floorboard. I'm assuming the heavy duty boots I usually wear for work were just dampening it where a pair of leather bottom cowboy boots allowed me to feel it pretty easily

I guess some more info is that the noise and vibration seem the worst at about 40-60 mph (haven't gone faster). Also the noise occurs regardless of throttle, in gear or neutral.

 

Bolts that hold the bed to the frame are loose.

 

Never would have thought to check that! That would explain why when my bed was loaded I heard nothing. I'll crank them down tomorrow and see what happens. I hope you're right because that will be a lot easier than anything I've been guessing it is.

 

You could have a couple buddy's come by in a car. You drive the car and a buddy drives the truck. Head down the road and you drive up next to your truck and listen. Turn off all sound systems so you can hear. Drive on both sides of the truck.
You might be able to narrow it down to a certain area better.

 

Thanks for the suggestions. Traveled to visit family, had to take girlfriends car, so have been gone for 5 days. Going to start the elimination process tomorrow, so if anyone has any other ideas keep posting and I'll let you all know what I find.

 

My truck made a similar noise when a wheel bearing went out.