First I have researched this and there has been no conclusive answer so I figured I'd try posting a thread.

Currently my car has a noise and I'm trying to nail down the solution. Recently I took a trip and after about 120 miles cruising 80-85 the car started making a whining noise, that is generating from the rear. We put the car on the lift and it seems the noise is coming from the diff. Without the stethoscope it sounds like it's coming from the back of the drive shaft/the front of the diff but when putting the stethoscope on the front of the diff it sounds like a whirring. The noise changes pitch depending on speed from a cat howl to a high pitch whine but only under throttle load. The volume is loudest when throttle load is enough to sustain speed but goes away when the clutch is engaged or when there is no throttle applied. I just ordered all new bushing for the rear subframe and the diff mount bushing as the bushing is blown. I do know that the diff mount bushing wasn't blown when we changed my diff fluid a month ago.

The car is an 05 35th with 91k miles.

Any help/advise would be appreciated.

 

use the proper nissan diff fluid, that will quiet it down quite a bit.
has the fluid ever been changed? If so, what fluid is in it?
What kind of bushings did you order?

non oem ( poly or alum) bushings will increase this noise ten fold.
Its the reason OEM is such soft and isolating rubber.

learn to love it.. thats the noise any muscle car worth its salt makes.

 

Flimsy,
My '04 with 115k miles is doing something similar. The whine is most noticeable around 50 mph on smooth asphalt. I asked the dealership to look at it. They said they used a stethoscope, and that the noise was coming from the differential. They said I need to replace the whole rear-end, for $2400!!! Luckily I have a friend in the parts department, and got a significantly better price.
The thing is, I find it hard to believe that I should replace the whole thing.
Please let me know the result of replacing your bushings.
In all your research, what have you learned about replacing the gears?

Thanks

 

Unfortunately the sound you are hearing is your pinion bearing in your rear end. You can replace your entire diff and not pay 2400, but that is what will have to be done. I am buying another diff and swapping out to run a 4.08 gear.