Differential Noise (New Gears)

[Yardsale]

'01, Job 1 4x4.



Last week I had the differentials re-geared to compensate for taller tires. When I first drove it, I heard a whining sound from the rear when decelerating. I recognized this as the gears. I engaged the front and heard a similar sound.



I called the shop that did the work and they said to bring it in for a test drive.



After the test drive, they told me the noise was not unusual. When I asked why, I was told that this "is the difference between a $200.00 and a $400.00 gear set, like factory parts". I asked "So, the factory actually makes some parts that are of higher quality than the aftermarket manufacturers?" The response was that the factory engineers for quiet performance because they can't sell cars that make noise.



I'm pretty sure this story is supposed to placate me. I'm also pretty sure it ain't true.



I believe that either it is the setup between the ring and pinion gears is not correct. I don't believe that aftermarket gears are inherently noisy.



If it is true that there are choices between gears sets that make noise and those that don’t, shouldn’t the shop offer me each and let me decide what is my preference?





Votes??

 

[EddieS'04]

What was the brand gears installed? I suspect faulty setup or damaged bearings during setup..Did they use new carrier bearings?

 

[Todd Z]

If you installed Richmond gears, then this is 100% normal on deceleration... They are noisy and suck....



Also a set of 4:56 Ford motorsport gear set is only $200.00 so the Richmond's are about $175.00 at summit racing....



Honestly he is right...



Also what did you do to break them in ???



Todd Z

 

[EddieS'04]

Todd, I was running richmond 3.73 in my '94 stang. I had no noise..

 

[Yardsale]

I didn't get the brand of gear(my bad).



I heard this noise from the first drive and it has not changed much, if any.



The break-in:



Initially below 45 MPH and varied speed for about 20 miles with slow acceleration and breaking (new brakes, too), stopping at lights. Let it sit for about six hours, then drove it about 35 miles about the same. Drove like this in 25 to 35 mile drives for about 175 miles, then slowly increased the top speed about 3 or 4 MPH each drive after, always taking it easy.



So, it's true that some gear sets make more noise than others. Okay. Should I have been savvy enough to insist on "quiet" gears, or should the shop present me with the options, or, are they operating their shop based on what most people want and the option isn't offered (any more)?



Anyway, it makes more noise than I want for my daily driver. I don't mind paying extra for quality. What are my options?

 

[Todd Z]

Ed, they can be setup to make no noise, but for the average Joe that rebuilds the ford 8.8, the Richmond's are noisy...



I had 4:56 in my 75 mustang, rebuild the rear my self, No noise..... It can be done, But for the guy that is simply setting it to spec is not going to care if you get noise..



Todd Z

 

[Yardsale]

I have been told by two friends who have built differentials and both say that, while some noise may be considered normal, they can be setup such that there is minimal noise.



I do not expect noiseless gears, but these make about three times the noise of the stock gears with 170,000+ miles on them.



Todd - I understand that some perform a simple installation, but what about the guy who owns the vehicle and feels that the noise is unreasonable?

 

[Todd Z]

You can try to talk common sense with the shop, explaining to them that this is not a loud mustang, but a daily driver. The noise you here is unacceptable to you. Plus the fact that no one ever told you about any gear noise.



See where it goes, Maybe they will be willing to do something...



TOO bad it was not a Disc brake rearend, I would trade you my 4:10 LS rear for it...



Todd Z

 

[Yardsale]

They have been pretty easy to deal with. I don't really have (much of) a problem paying a bit for (proper) setup. And you are correct - if they had told me, I'd have what I want and they'd have a bit more money instead of facing a loss due to rework labor.



I'll give it a shot.



If we traded, I'd have the 4.11:1 in back and the 4.10:1 up front. That'd be fun on ice!



Thanks!

 

[Todd Z]

oops, My bad, I have the 4:10..... I thought you went with 4:56..... Thats what i plan to do..



Todd Z