Driveline Growl

[Mr Book]

Hello everyone haven't posted in awhile but have a question, had my car looked at and was told there was a growl like sound coming from the driveline. I've heard the noise several times but it varies depending on my AC fan setting until the other night when I had my AC off and under med acceleration when heard it again, so would it be the trans ready to go or something else that could be going?

[Toasty]

are you sure it's not the sound of your electric fans being on? sometimes you can hear them when they're both on high.

otherwise, could be a noisy bearing in one of the idler or tensioner pulleys...