I just got my motive 4.10's and DTT put in today and took my truck for a couple easy drives to heat cycle and break in the gears. During those drives I noticed the gears whine pretty loud in a certain speed range, that is loud enough to hear over my dumped 14" magnaflow and the radio. They whine from 50-55mph in 5th gear, but other then that I don't notice any whine from them. Granted I won't be going highway speeds until I get through w/ the first 100 miles of break in so I don't know if they will whine at other speeds yet. Is this normal and should I be worried?

 

Contrary to what anyone tells you about aftermarket gears, they should NOT whine at all!
They've got your backlash off slightly. If it's slight and only at a certain RPM range, it may wear that high spot off and quiet down, but that job weren't cheap, you want it right!!!

 

Thanks for the reply Hammer, do you think I should take it back or give it some time to break in and wear off that spot? The guy doing the install actually overfilled the rear and said he took it for a test drive and he thought the speedo was off b/c it said 70 and he thought he was going 55 (he must be used to driving something lower to the ground). I drained off some of the extra gear oil down to the fill plug hole, but it's supposed to 1/4 below the hole on an 04 right?

 

That's scary because anybody knows anything about Dodge trucks and axles should know that the speedo is read off the ring, and gear changes have NO bearing on the speedo. ONLY tire diameter does.
I hope the hell he knew what he was doing. Dodge (AAM) axles require shimming where most others do not.
I'd have it check out fairly soon. A bad install can ruin the gears, and a really bad install can granade the axle...

 

Great, he said they've done plenty of regearing but that it had slowed down lately and I have used this shop for most other work on my vehicles as they have done a good and honest job in the past. I know a mechanic who could check the pattern, but he couldn't do the install b/c he didn't have the $400 pinion gauge set which was needed for this axle. The only problem is that his shop is gonna require me to take my truck on the highway to get to him and motive says no highway speeds for the first 500 miles.

 

Does the noise change as you get on or off the throttle lightly like from coasting to light throttle. Likely it does and if is any louder than a properly functioning rear axle you sir have some install problems that can turn nasty really quick if not corrected.

 

It's at about 50-55mph under light throttle/maintaining speed and coasting. I listened to a bunch of videos on youtube and mine is so quiet compared to them that I think it's probably not an issue. With that said I'm probably still gonna take it over to the shop and question them and take one of the mechanics for a ride to see what they think. Thanks for your help guys.

 

Aww man this has got me worried about my 4.56's I had installed a few weeks back. I've just come up on the 500 mi marker and I had a feint whine around 45-50 after install, but only under throttle and settled down after reaching 43. All throughout the break in phase can mettle shavings cause a feint grind noise under throttle . . . or is that signs of a need for a few shims ?

Holy s*** if this is what I think has happened I'm going to flip s*** I haven't driven it in a day or two been using my dads truck because of the 500mi mark I ordered 75w140 Mobil 1 oil for changing out the oil myself, so I'll try and warm it up and drive next to a wall because that's usually only when I can hear the ever so feint grind. This whole ordeal got me thinking of getting the Clear diff. cover from MoesPerformance.

Any advice ? (Sorry if this is thread jacking, I'm very worried about my gear install now. I'll be emailing them tonight)

 

Still though it is louder than stock was yes?

 

When I had my 456s done they also whined. I had to take it back 2x and it is better now.