Rear end Whinding???

[Loudmouth1o]

So recently I had gotten Ford Racing 3.73 gears put in my rear end, rear end had 20,000k miles on it and never made a noise before. After the gears when ever i go i dont hear a thing, then i let off the gas and coast all i hear is a loud whinding from the rear, i figured it was the gears getting broken in so i kept drivign 2 weeks later and around 400 miles on them still same loudness coming from them. Is this normal? what can i do to fix this?

installed was 3.73 ring and pinion, 8.8 gear girdle-ultra low, 8.8 pinion bearing and 75w-140 gear lube, also installed that day was my ford racing intake manifold. Any insight and ideas are appreciated.

 

[GrnBullitt08]

The 3.73s should not make any noise. They were installed wrong.

Check backlashing and pinion depth. Also did you install all new bearings and races with the ring and pinion?

 

[Loudmouth1o]

Instal was all done by Blow by Racing, ill have to give Chris a call and see what he says, the noise is killing me expecially cuz i love to drive with windows down

 

[GrnBullitt08]

That's actually surprising considering it was done by BBR, definitely give John and them a call I'm sure they will be glad to help ya out. Pinion depth, backlashing, bearings, and pinion bearing pre-load could all be culprits of the noise

I have heard of the ring gear bolts coming loose which to could lead to some whining issues as well.... That would through off the backlash

 

[Redfire_WNL]

I am having the same issue but mine is going back to installer this weekend and if he can't fix it then it will be going somewhere else.

 

[Rollins097]

i had that issue with mine...started making the noise not long after i bought it, with teh stock gears..I took it to the dealer and they rebuilt it....replaced all three bearings and the ring and pinion...something just wasn't aligned right....

 

[kevinatfms]

WOW, i cannot explain enough.

thats pretty amazing how they setup your rearend wrong...i wonder if they used the correct tools?
i hope they reinstall them correctly with the correct tools...pinion depth is critical on our 3link rears. the upper link transmits the rear end NVH like crazy due to mounting position on the body. if the pinion depth is off just a hair(0.005) or more you get a whine but it will be amplified x2 due to the 8.8 housing change from 05-up.

also make sure they did not install the 8.8 high torque bearing without the spacer plate. the bearing and race diameters are different and if you use one with the other it will set the pinion preload off and torque specs for preload to be off.

 

[Loudmouth1o]

^^^ thank you for your input and knowledge on this subject for i am young and do not know much with gears. I called up john today and he said they will be more than happy to take a look at my gears as soon as i can get to them.

 

[MUSTANG16]

I didn't want to start a new thread so I don't drive my car much or very far. The other day I had no choice and drove it 160 miles round trip.
When I got back on cape I noticed when coming to a slow stop something slipping or catching on the left rear.
I just went to fill up this AM and its cold out. I didn't hear the noise. So I'm guessing when the car is at high temp., the noise will return. I checked my torque mark on the PH bar and its good.That was the last thing added back there.
Do I just keep running it till it breaks or what thanks