I have the same issue (creaky clunky noise) when traversing off camber situations. When the right rear is higher than the left rear or vise versa.
The parking lot entrance at my work has a sharp grade, when I enter the lot off the street, turning right, every once in a while I get the noise. A metallic snapping type noise. Does not sound good.

 

I have this same noise when turning into an entrance with a little bit of a drainage ditch or sort of speed bump type entrance. Would love to hear from anyone that has a diagnosis/fix.

 

Took mine into the dealer today for 3 things.
1. trans flash
Flashed tranny and said to drive for 20 miles to "make it learn".
2. rear end squeak
Some kind of adjustment and grease. No more noise.
3. "09" button on keyless entry does not light up.
parts ordered.
4. Windshield crack. I think the windshield is defective but they said it was a rock.

3 out of 4 isn't bad.

 

Check with your insurance company to see if broken glass is covered on your policy. I have it on mine under comprehensive. "Glass Doctor" came to my crib and replaced the windshield in 1/2 hour. Didn't have to pay any deductable either. State Farm is my insurer.

 

Rear leafs disassembled again this week, lubed and reinstalled. Dealership thought it was fixed but when I bounced the rear of the truck....squeaky....squeaky....squeaky. Had the sales manager and service manager out to have a look and they all heard it. It was even worse this morning. I have to return the truck next week for them to pressure wash the gaps in the leafs and apply some type of special grease. This will be the 4th time the truck is in for the same problem and we do not lemon law here in Canada!!

 

They need to replace your leaf springs not just re-lube them. Same thing happened to me when my truck had only 5000 miles on it. They first tried lubing them, the squeak went a way for a couple days then came back. At that point they replaced them. 2 years and 20,000 miles later I haven't had a single issue.

 

Had them done already. Here is the milage (+- 500kms) timeline!!

1500kms - rear leafs lubed...still creaky
4000kms - rear leafs replaced.....2000kms later....squeaky
7200kms - rear leafs lubed again....creaky...creaky....
TBDkms - dealer called Ford and they said to take the truck back in and pressure wash the springs and lube with a super grease that is currently on order....

If this doesn't work I will be buying a new Tundra!!

 

Wow, that's insane. I'm sorry. I hope they get it fixed for you. I'd say, maybe try a different dealer. Maybe these guys are doing something wrong?