Lsgun1

Could be an injector too.

Ok I would be mad as well. I wouldn't just replace it since the truck is driving ok just shifts a little different. Try a flush and see what happens.

Fluid wears out, just change it and be on your way. You want to fight over a couple hundred dollar service that is supposed to be done regularly anyways. https://my.gm.com/content/dam/gmownercenter/gmna/dynamic/manuals/2016/Chevrolet/Silverado/2016 Chevrolet Silverado1500.pdf There's a service schedule

Expensive. Go through insurance cause of of pocket will hurt.

Serviceable as in replaceable? I don't see why not.

Before the new one goes in just change the cam and lifters to delete the AFM. Now you're back to bulletproof 5.3

What kind of tires? Run your hand over the tread, if its all bumpy feeling then yes you can be hearing tire noise, usually mud terrain tires will cup/feather like that.

I wouldn't go into the transmission, I doubt it's inside. You've already thrown to much at it with no results so a real diagnosis is what is left not a "we think it's this with no guarantee". You can use a soft face hammer and tap all over the truck (some places harder then others so you don't cause damage) to see if you can replicate any rattles. Have you looked at the flapper valve on the exhaust?

If your old truck made 240k with no issues I think you know what you are doing maintenance wise so keep it up! Also I run the same Range module to keep V4 mode off simply because I don't like it. Will it hopefully keep any lifters from having problems? I don't know, I hope so.

Completely normal for the hubs to be hot. To figure out which side is making the noise just drive the truck till you get to the speed you hear the humming and start turning the wheel. If you turn the wheel right and hear the sound then the left hub is bad, if you turn left and hear the sound then the right hub is bad. You are essentially loading one side more then the other.

That rattily sound? Kind of sounds like a heat shield on the exhaust that has broken a tack weld.

Sounds like a wire in the door harness is pinched or partially broken. Open the door and you'll see the rubber boot that covers the harness, pull it back and look at the wires. It may not be obvious at first.

Its likely the leaf springs. If you jack the back of the truck up by the frame they will sag and you can pry them apart to clean the plastic pad that separates them. If you put a piece of rubber like a bike tire on top of the pad it won't come back. Very easy fix to do yourself.

What about it?

I agree its the leaf springs making the noise, mine did the same thing. Jack the truck up by the frame so the rear will hang and keep tension on the leafs minimal. Get a pry bar and pry the springs apart and you'll see a plastic pad, clean it off and put a piece of rubber in there then pop your pry bar back out. Do this on all 4 pads and you won't hear the noise again.