Loud humming when taking foot off
gas
it might help if you gave us a hint of where you here the sound coming from.
Check for exhaust leaks, or loose sheet metal on the exhaust system.
Or could be a differential failing. Should it be assumed the noise is in the front?
We also need to know if the sound occurs when the vehicle is stationary, or when it is moving. If it takes place when the vehicle is moving, is it speed dependent? In other words… does the sound differ at low speeds and at high speeds?
Probably an intake resonance.
In an attempt to help, every response has consisted of more words than the OP’s “question”.
Perhaps we should wait for the OP to provide more details before we throw any more guesses into the mix.
Been three days, no response from the OP.
So here is my response to the statement.
It hums because it does not know the the words.