drivetrain help!

[BullittStangV8]

okay guys i got my 4.10's put in, and now whenever i hit around 2000 rpms and stay there (like cruising there) i hear a "wiiiiiiiiiirrrrrrrr" comming from the rear end.. its not terribly high pitched, but its constant when i get to that rpm. I dont really hear it below that rpm, and when accelerating through the gears and shifting when driving moderatly i do not hear it. Is it gear whine? do i need to have the gears reshimed? if so how big of a deal is that?
Mike

 

[AirWolf87]

sounds like good ol gear whine. I dont think its a real problem...more of an annoyance. IMO, i dont think you should be worried

 

[BullittStangV8]

common guys i need more opinions.
Mike

 

[01LaserRedCobra]

I have the exact sam problem. It's only at cruising speeds when it happens. I am wondering if the backlash in the rear gears maybe set incorrectly, or needs to be re-adjusted.

 

[blkhorse]

did you install them your self? what brand of gears? what was the backlash before and after install? and finally is the whine under coast or power condition. my guess is incorrect backlash(if frpp gears) they seam to like .012in lash installed at lot of them and never had a whine

 

[BullittStangV8]

I got them installed at JDM Performance. They are FRPP 4.10's. I send them a PM asking what they set the Backlash at, hopefully ill find out monday. The gears whine when im in gear crusing at about 2000 rpms. If i clutch in, it seems to go away? does this make sense? Also, i took the car up to 85 mph today, and the car started to shimmy from the rear...more result of the gear install..?
Mike

 

[ironmedic]

thats normal, u will get gear whine all the time. it depends on the backlash if u will get a small amount of it or barely any. my old 5.0 had 3.73's that screamed and i just dealt with it.

 

[blkhorse]

if the gears are installed correctly,you will NOT get gear whine,4.10's will not whine more than 3.27's. I have installed gears from 2.73 to 6.14 with no noise. have them test drive your car and show them your concerns,the longer they are run the harder it's gonna be to eliminate

 

[BullittStangV8]

The thing that alarms me more then the noice itself was the vibration im getting above 85 mph..the whine is annoying, but the shimmy seems dangerous/ a sign of something seriously bad going on. Ill talk to JDM tommorrow, hopefully they will stand by their work and fix it.
Mike