09 2dr auto with 3.73, 2.5" coil lift on 35's, just hit 40k miles
Getting a bad wine and hum somewhere in driveline only when giving gas and above 1500-ish RPM's. Hum stops the second I am completely off of the gas. Ran about 40mph down a hill in neutral giving gas and no hum. Please help me out guys.
My first thought was rear drive shaft which is still stock. Can not see any grease or tear in cv boot. Shaft is always roatating even in neutral so that rules that out correct?
Second thought was gears but do not see any oil outside or around diffs - have yet to check oil level though. Again, gears are always rotating so if it was them the wine would be constant regardless of amount of gas and or being in neutral, correct?
Last thoughts and now worried that it may be something in the tcase or transmission. ATF fluid looks good, doesn't smell burnt and doesn't feel gritty.
I have to imagine that I'm on the right track, but really could use some help on where to go and what to check next.