Humming sound coming from the rear end

[1999hoe]

I have been noticing a humming sound while coasting in my Tahoe doesn't do it when I touch the gas

 

[retiredsparky]

That is likely differential gears getting worn. When gears are loaded, they are in better contact with each other which cancels out the noise. When you are coasting, the slight howling noise you hear is a type of harmonic vibration transmitted through the frame and body. If you replace the differential lube, it is likely it will continue to run for years. There are shops that repair differential gears.

 

[1999hoe]

Thanks for the reply ....im gonna change fluid and see if it helps any recomendations ?

 

[AppocAlexx]

Do fluid and some rear end additive. Some fluids say that it comes with it already in it but add more of that stinky stuff in there and it may help your situation.

For the most part depending on how loud the whine is, you may want to start accumulating parts for a rear end rebuild. You may just be putting a band aid on it by changing fluid. And a busted rear end will cost you more money and time left on the side of the road. Just my .02c

 

[1999hoe]

Thats exactly my plan tho ill probably just swap rear ends with something else but for yhe short term im gonna change the fluid and see how she sounds