"They all do that" is what all dealers say because they don't feel like fixing it. Take the 11th gen trucks with the 5.4L engine tick from the problematic cam phasers. "They all do that" does not mean "they don't need to be fixed."

 

For those that are experiencing the whining sound. Which rear end do you have?

 

You make a good point. Friend that is a GM mechanic basically told me similar thing. It doesn't pay enough based on time to do it correct and most mechanics rather not do it.

 

IMO …..If properly assembled per spec’s it isn’t normal for rear-end to whine. More than likely backlash not properly set, ring and pinion gears not properly cut or incorrect torque load on bearing. These settings / tolerances are measured by .001” and is critical. Has to be done by a trained technician or your problems could be worse. I don’t have a any faith in my dealership to even change my oil, which is why I have been hesitate to pressure them with the whine coming from rear-end. From other post I have read of Ford replacing several ring / pinion gears due to noise.

 

Not sure what is going on with the rear ends. I can assure you the mechanics are not trained not to hear the noise, but bad mechanics tend to not hear the noise if they don't know how to, or don't like doing crown and pinion gears Sometimes it can be hard to determine if in fact the noise is coming from dif, transfer case or trans if it is too faint. But there are other tel tale signs you can use to pinpoint.
Try another dealer.
BUT, I had a whine from new. they did change the gear set when they finally got their hands on one, but shortly after replacement, the whine came back, only now under decel. (first was under acceleration). Dealer says too faint to tell where it is coming from , but it is the rear end. So you may want to get your whine noted on paper with Ford, but wait till they have an answer, and a fix if there is one before wasting time.
I have seen a few vehicles over the years with rear end noise, but many miles, years later posed no problems.

 

Sounds like a ring and pinion whine. I've assembled quite a few 8.8 Ford rear ends in 5.0 mustangs over the years. My own car was the one I learned on lol (I am a licensed mechanic, not that that means I know everything lol) . I've been told by people a lot smarter than me, that every gear set will whine at a certain RPM, ideally at an RPM the sound isn't noticeable. The whine is just the harmonics of the gears.
What I've learned from experience, is that more backlash = noisy gears... Meaning the whine happens at a slower speed, and is more noticeable. I also can say, the steeper the gears, the more noise they will make.
When I set up my first gearset, a 3.55:1 in my mustang, the backlash ended up being at the upper limit of acceptable. The gears whined at 70kmh, drove me crazy. I drag raced that car for years, and never had a problem, it's still going 15 years later.
Not suggesting a noisy differential is OK, just saying I doubt anything bad is going to happen providing it has oil in it. The dealer probably doesn't want to touch it, because setting up a differential is abit of a lost art. They would have to replace the gears, as you can't change the wear pattern once the gears are run in. And the chances of them making it worse are pretty good.
My own personal experience is that the tighter you set the backlash, providing the wear pattern is ok, the quieter the gears will be. This being said, the dealer is likely to say it's normal, if they see no risk of failure. Odds are there's a 50/50 chance they will make it better if they try.

 

man I can feel that noise in the base of my skull lol

 

usually rear pinion noise stops making noise when you let go of gas pedal and starts again when you give it a bit of throttle...yours do that? if not it could be a wheel bearing front or back...wheres the sound from?front or back?

 

Your right, you can usually play a tune with the accelerator lol. That noise could be from something as simple as a scalloped tire. I've even seen certain road surfaces sound like that.
Take it to the dealer, ansdask to take the tech out for a drive and demonstrate the noise for him

 

I agree scalloped tires can make a lot of noise, but I am certain this isn’t my case. Been whining since around 800 miles on Truck with Michelin LTX. Noises has been isolated as coming from rear even after tire rotation. Truck now has around 5800 miles on it.

I can manipulate the whine when slightly accelerating / decelerating. Not necessarily gain / decrease speed, but more of a torque / no torque ( hope that makes sense ), however at around 60 -70 MPH it tends to be constant. At slower speeds of 40 – 50 MPH it seems to whine more so under deceleration.

Beings my pinion angles is out severely I was hoping dealer would correct the angles with possibility of eliminating the noise. However the dealership has basically refused to check the angles even after I told them I had personally checked angles myself and know they are out. Trans down @ around 4.5° , pinion up @ around 1.7° and drive shaft @ 5.8°, Working angles of 1.3° and 4.1°. After 5 visits over vibration and whining noise….. they still refuse to check angles ( Said he don’t have the tool and doesn’t think the angles have anything to do with vibration ). Service manager finally acknowledge the whining noise and said he would check with Ford and get back to me. I have not heard back from him and it’s been several weeks.