Hi guys I have g37 coupe 6MT, and I apologize for listing a question on 350z forum. But I think you guys may have more knowledge about mechanical things.

So I recently repaired the rear differential bearing due to the humming noise when gas is applied at high speed. My mechanic suggested to replace worn out bearings, so I just replaced them. It was okay for a while.
But I started to hear a similar humming noise(it is not loud but noticeable in quite condition) only when I step off from gas pedal.
I am suspecting either improper replacement of rear diff. bearings or driveshaft compartments. But still have no clue about the noise.
Which part should I look first in this situation? Any suggestion or help would be appreciated!

 

Only when you let off? Gotta be the ring and pinion. Maybe the bearings are worn, maybe it's out of oil, maybe it isn't set up right. I would at least get underneath and wiggle things around for your own safety.

 

if you have a 37... the bearings should still be good the car is not that old. i honestly dont think that is the issue, think you mechanic was guessing. did you see the old bearings? the g's have an articulated drive shaft, not sure if that would cause the noise or not. usually the diff will make noise if the gears and all the inners are not shimmed/aligned properly

 

The 37 has a carrier bearing on the driveshaft? Maybe it or it's housing are to blame?

 

i know the 35's do.. so i would assume the 37's do also.. i hear if you get a solid driveshaft for em it make a HUGE difference

 

thanks guys I think I should blame my mechanic first. And definately gonna look for any wiggles for sure. hope not it's a big problem.. Thanks again!