Thruxton900

Hey all, I've had my 2013 5.0 6spd for a few months now.

When I'm on the highway in 6th at around let's say 80mph, the whine from the rear end is pretty loud.

Now, I haven't had an 'Merican car for a while (used to have an S4), but it seems a little loud.

Everything is performing just fine. Just felt it was a little too loud.

Is this normal?

JIM5.0

Loud is relative. What might be loud for you might not be he same for me.

I had gear noise problems in previous cars (not Mustangs), and basically, if the whine is louder than the outside air rushing by your car at 60 MPH or faster, the rear gear is chewing up its teeth. It's time to rebuild the rear end.

If this is the case, take it in now to fix because it will only get worse and become more expensive to repair. If left to the point that your car begins to vibrate, a complete rear end rebuild is needed and that will cost you over $1000 to fix at a shop. The bearings by that time are shot and have wreaked havoc to everything in the diff housing and your axle shafts.
If your car is still under warranty, take it in immediately to have a look and repair if necessary.

Slow*Jim

I think whine at lower speeds is typical but I don't hear any above 30 or 40mph. I would take your car into the dealer

Lethaldosage423

What gears do you have in the rear end?
I have the 3:73 and in 6th about 80, i also have a whine

I installed a whiteline upper control arm and the whine was ear piercing so i put the stock one back on. Still unsure if the whine is normal of the gearing or not.

Inspite

My pinion seal went bad, the oil leaked out and I developed a whine. Took it in and they fixed the seal. 8,000 miles later the whine came back. It got real loud, like embarrassingly loud, and I took it in. They replaced most of the rear differential. Now i'm 8,000 miles after that, and I have the whine again. I just made an appointment to take it in. I have 331 gears.