2010stanger

OK guys i've been hearing a humming noise that seems to be coming from rear end when i reach speed from 60mph and up and pressure on gas pedal. As soon as i let go of gas noise is gone! dealer has said that the rear diff is fine and noise is coming from exhaust resonance. is this possible?

Unleashedbeast

if the whine increases the pitch as you drive faster, and changing the gears make no difference in the pitch...you have differential gear whine.

2cokeman

Stock rear??

2010stanger

Yes i have the 3,73 rear end, noise only starts at 55mph gets at its loudest at 60mph and then noise dies down at 70 mph but can still hear it a little. Dealer is telling me that its a mix of muffler resonance and drive train resonance.

grabber blue gt

https://mustangforums.com/mustang-ts...XLE-WHINE.html

Blacksmoke

YUP!
Also... you could try adding a bottle of Motorcraft Friction Modifier to the rear end.

Many GT500's have a groan in the rear axle that is fixed by this so it MIGHT fix your problem. If not I'd do what Grabber said above and get the TSB done.

Unleashedbeast

Yep, that's gear whine. The noise gets louder within that range because the frequency of the noise gets into the more sensitive frequency range of your hearing. The faster you drive, the higher the pitch....the less you can hear it.

Try the dampers, if that doesn't repair it...you need your gears setup again.

2010stanger

Damper were put on and didnt help! i went to 2 different dealer and they said that it was resonance and will not open up rear for no reason.

2cokeman

Sounds like it is probably gear whine to me. try another dealer if you can, Go to aftermarket shop just for an opinion?

grabber blue gt

Not sure on what to tell you, but I know no dealer wants to take apart a rear. My car has been in the dealer this entire week having the rear rebuilt, so its not something they want to do. Its DEFINITELY gear whine, cause if you have a stock exhaust thats bullsh!t if theyre saying its resonance.