so ever since i got my yota a week ago when i hit about 15+ miles per hour it starts making a banging noise but only when i hit the gas,the second i let off the gas it goes away and i cannot figure it out it sounds as if something is spinning and banging against something else

i have already checked tranny mount and front driveshaft but it sounds as if its coming from the rear end
and advice is great thanks

 

Sounds like the rear end. Pull the drain plug on the housing and see what "falls" out.

 

u joints ?

 

is your driveshaft attached at both ends?

 

Jack up the rear end (both tires) run it in 2wd and listen.

 

checked u joint too but i will try jacking it up asap to check it