Hey all,
I have an 03' G35 Sedan with almost 138K miles on it that has a humming noise that seems to be present when I get near 40MPH and increases from there. It's coming from somewhere in the rear of the car. I had a mechanic look at it and he thought it was a wheel bearing so he started to replace one of them and then he said it wasn't the wheel bearing but a bearing on the rear differential. Does this sound right? I'm wanting to get it fixed and want to pinpoint the problem before doing anything more. Any advice would be much appreciated. Thanks

 

The G is notorious for gear whine from the differential, I've never worried about it honesty lots of rear drive vehicles are noisy like that but the G is particularly noticeable because there isn't anywhere for the sound to go except into the cabin.

Wheel bearings also whine sometimes when they start to fail, so can the propeller shaft center bearing so inspect or replace those items if they have high miles, change the fluid in the differential if it's due and just drive the car.

 

Thanks that definitely is reassuring. I appreciate the help.

 

How many car owners change their differential fluid ever, unless you're a car freak like myself! Trans fluid should be changed more frequently than the 3 years 30K miles Nissan suggests! Differential fluids s/b changed as Nissan suggests but how many owners do that? I would also suggest using Red Line synthetic fluid in the differential since it runs cooler/cleaner!
Gary