2004 g35 coupe

when driving i'd say over 35-40 mph + i have this road noise or humming noise coming from i'm assuming my rear differential. at first i thought well its the tires but there brand new. and then the noise decreases as speed does and increases and speed increases.

what could this be a sign off? diff rebuild? bad diif oil?

i'd appreciate any suggestions. Thanks in advice

 

If the new tires are from a different manufacturor, it could be them.

 

all 4 tires were replaced at the same time..same manufacture

 

when was the last time you changed the fluid in the diff?

 

Wheel bearings? The rears sound like they are coming from the differential.

 

How can you tell if it's the rear dif or rear wheel bearings?

 

I have this noise too and I changed the dif. oil and the drain plug had a lot of metal on it. The noise did not improve even with synthetic. If I get new differential with my aftermarket warranty and upgrade to LSD will I have to change axles?

 

I have the exact same problem. 98Kmiles on my 2004. Will post back when I have a resolution.

 

I am taking mine to the local Nissan dealership Monday.

 

If it is the diff, do not waste your money rebuilding it. You can buy used ones for $300-400. I bought my 3.5 VLSD diff with 40k miles from a local auto recycler in Topeka for $300 and swapped it myself in 3 hours. It's easy. There so few rebuilders that can get the gears to seat right without noise and you can be assured it will cost you way more than $300.

 

DaveB were you able to reuse the same axles?
Since mine is going to be a warranty (aftermarket) repair I'm not sure how much control I have over how the repair is done.

 

I have the same noise under acceleration in second gear it is most heard. the faster I go the noise goes away. mine is an 03 85k imles.

 

Yes you reuse the same axles.


Typically the humming diff means low oil. Or bad wheel bearings, to tell if it is your bearings Jack up your car and try to wiggle the wheel side to side if it moves you may need your bearings replaced.

 

OK, the noise I thought might be the differential turned out to be the right rear wheel bearing. It's replaced now and all is well. The junk that came out of my differential still concerns me so I am going to change to fluid again real soon.

 

how much play did you have on your rear wheel? did the noise go away the faster you go or just got louder? I am still trying to find out my issue.