Differential Unit problems of the 2010 Toyota Tundra

Excessive rusting on rear differential, leaf spring mounts and around rear hubs to wheels.

While driving my Tundra 4wd I notice a growling/howling coming from the front of the vehicle. It causes a vibration at speeds from 15-30 mph, it happens in 2wd and the howling is noticed mostly during acceleration and deceleration. I have taken the issue to the Toyota dealer twice for the noise and they said it was normal and was told it was the tires I was using. I swapped tires with a friends truck and had the same issue. What I'm hoping is that it isn't something out of alignment in the front differential housing or axle. I would hate for it to come apart or lockup and put me and my family in an unsafe situation. I saw there was a service bulletin out for 2008 Tundras for the same issue with steps to correct the problem. I haven't seen a service bulletin for 2010 Tundras and want to know if it even exists. I hope this issue will get looked at because being told "that there is nothing wrong" at the dealership is getting frustrating. I can't believe a truck with now 28450 miles is having issues already. I hope this issue will be looked at in the future. Thank you.