When I remove my foot from the accelerator I get a loud rattle noise? Driveshaft center support bearing?

Can you please shoot a quick video with your phone so I can hear the noise? That way I can tell for sure what's going on. You can upload it here with your response. It sounds like you have a cracked flywheel but for me to tell for sure what's wrong I need to hear the noise.

Can't really get a good video of the sound while driving but you can hear it a little in this one.

Thanks for the video, it sounds like you have an exhaust system shield that has come loose or a catalytic converter that has come apart and is rattling inside the exhaust system. I would use a rubber mallet and get under the truck and band on the exhaust system from front to back to see if you could duplicate the noise and get back to me with what you have found.

So, would the exhaust system make that humming noise as well? Also, my converters have been removed. I will see what I find and let you know. Thanks for your time. It's greatly appreciated.

Is it possible for the u joints on the main shaft to make that much noise?

Yep, the humming noise I noticed but I thought it was the rattle noise you were talking about. Check for a rust-colored dust around the U joint which is sure sign the U joint is no good, you may need to remove the drive shaft to check it fully. Is the truck lifted? If so, then I would suspect the U joints, Also the noise can be the differential as well, remove the rear cover and look for metal shavings. These videos can help:

https://youtu.be/6F26Kir0OCg

And this is on a similar truck, but the procedure is the same.

https://youtu.be/p2snOCyqVMY

Please run down these guides and report back.

Okay, so, no, the truck is not lifted. I have pulled both driveshafts and checked the u joints and they all seem fine so I'm going to remove the cover on the rear end and check that today. I'll update as soon as I get cover off.

sounds good.

Well differential looks good so that's out of the equation.

yep, it looks okay, refill with new fluid and take it for a drive to see if that helps. While you are at it inspect the underside to see if anything is obviously wrong.

Still the same. Nothing I see that's wrong. So, I guess I'll go back and check and verify that it's not your first guess. If you any videos or Info on accessing the flywheel that would be great. Any chance the driveshaft itself would make those noises?

Or what about the torque converter?

I don't think it could be the driveshaft, can you tell where the noise is being generated? It could be a clogged transmission filter.

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Let me know where you think the noise is coming from?

Okay Ken, I got home today, and I put my jack under the rear axle and jacked the truck up far enough so that the back tires was off of the ground, and I had my friend's mom push on the gas while I got up under the truck to locate the exact location of the noise. After doing that I do think it is the main driveshaft. I'm attaching a video so you can tell me if that's right or not.

Here is another one.

Oh boy, yep it looks like the driveshaft carrier bearing is out, thanks for the videos they helped. Here is how you can change the bearing out, start by removing the driveshaft. If you don't want to do the bearing an automotive machine shop will do the job for you. Check out the images (below). Please let us know if you need anything else to get the problem fixed.

Well, now that I have thought about it, it did seem like something inside the rear driveshaft was falling side to side when I would move it around. But at the time I just thought it was the yoke.

Disregard that last response, lol.

Let me know after you change the bearing if the noise goes away please :)