Steven6095

Hello
Long story very short
dealer tried 3.73 isntall 4 times still whining.

I took the car today with a new set of Ford Racing 3.73s and a full bearing kit, to Modular Depot in Cincy.
AWESOME people and their credentials speak for themselves. This place knows what they are doing and has the magazine articles, wins, etc to show for it.
They examined the dealer install and said it looked fine.
Two of their guys put the new gears in, new bearingsand even used Royal Purple fluid.
Still whined and now a little bit of chatter. These gears are in perfect, they have done them before in 05s, etc. Yes they have donesilent Ford Racing (motive made) installs.
I know you all were not there today, but there is no doubt in my mind they are in correct.
They are stil whining. One gentleman said they were literally the loudest gears he ever heard even with his race cars.

Current thought it this, the carrier is out of round or not weighted evenly all the way around.
They are obtaining a new t-lok from Ford Racing and we are going to try that. Everything else in the housing was replaced.

Just wanted to throw this out there. I may not be the only one facing this.

troyclemens

i installed 4.10's in wifes car 2 weeks ago, and found i could not run the lash suggested on the ring gear. What i found was that the axle tubes are not true in comparison. So, i threw out thier dimension, and once i had the pinion depth right, i just blued the gear in correctly, Turns out about .007 different. 7 thousanths may not sound like a lot, but with gears, it is. When they test and match thier sets at the manufacturer, the tubes, tube angles, and especially the ring mating surface do not come into play.
Anyway, that is what i found, maybe it helps?????

richmod

Okay, please forgive me for this stupid question, but where and what exactly is the carrier? I'm having major gear whine issues (4 attempts to fix have failed), and despite my best efforts to understand, I am still unsure exactly what and wear the carrier is. A photo would help.

Steven6095

Basically it is what the ring gear bolts to

As for the install - once by the measurments and once by know how / skill.
This noise is horrible. Way too loud for normal gear whine. I thought so and guys who build race cars thought so too.

richmod

Is it possible for the carrier, not the gears, to be the cause of a decel whine?

Steven6095

Doubt it. Mine are whining CONSTANT and whine is such an understatement

vb101

I've had the same problem with my 7.5" rear. Tried three sets of gears and four different installers along with an Auburn Pro lsd with no success. Personally I think it's just a poor design all the way around. From what I've read on both the V6 and the GT model it's hit or miss as to whether you'll get a rear end that will not make noise with a gear change. I haven't read of anyone with one the noise problem after a gear change getting it quiet again. I know mine made no noise at all until the first gear change and now I can't get rid of the noise for anything.

troyclemens

gear noise and whine are kinda 2 different things. Gear noise is a mechanical noise and can be from all sorts of isues, even bad bearings, or too much load on the crush sleeve.
Gear whine is kinda different. Gear whine is a harmonic noise, and it can be a ssimple as the way the gears are cut, and the meshing surface. Is you whine constant, or is it just on the coast side????? If it's just on the coast side, and it's a whistle almost, you probably don't have a problem, you just have gears that have a lot of maching hatch on the mating surface.

06hoss

Hey Stephen, I'm in the Cincinnati area too and I intend to take my car to Modular for headers and gears.
I've been talking to another local who basically had his stang built there and he's blown. He can't say enough good things about them. The thing that you might or might not know about the 3.73 Ford Racing gears is that the 3.73 is machined using a different process than their other gears. It's machined using a single pass process (called the Hob process I think). I'm just throwing that out there because it could possibly be the gear machining. I was thinking of going with 3.73s myself, but I will probably have the ring and pinion run through the Mikronite process first to strengthen and smooth the gears. If you're not familiar with that process check it out here: http://www.mikronite.com/Good luck with the fix!

Steven6095

3.73s for the 7.5 are not made with the new face hob process : (