# grinding noise at low speeds and humming at cruising speeds



## sutherlacd27 (Apr 12, 2010)

I understand how hard it is to describe noises over a forum but hopefully somebody can lend me a hand here. When I get below 10 mph and am coming to a stop I can hear a grinding noise coming from the rear. And then when i take off I hear it for a few seconds after. Then once I reach about 25-30 mph and up i hear a humming noise coming from the rear. and its not a faint noise. sounds almost like when a bike rim is bent and the tire rubs against the frame. ive jacked up the rear and spun the wheels and heard nothing and the wheels spun freely. also when im making a left turn the humming noise goes away and it gets louder when taking a right turn. wheel bearing? u-joint?


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## sutherlacd27 (Apr 12, 2010)

also, there is a faint vibration i can feel in the floor board but its barely there. another way to describe the humming noise seems like really loud road noise from noisy tires.


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## Poncho Dan (Jun 30, 2009)

It's either the wheel bearing or the CV joint. See if you can replicate the sound with the car in the air, if possible. Also, improperly torqued lug nuts will do it.


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## jpalamar (Jul 22, 2008)

When you jacked the car up, did you have any play in the wheel?


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## sutherlacd27 (Apr 12, 2010)

no play in the wheels when it was in the air. so its making me think possibly not a wheel bearing. the grinding i think might be brakes so its getting done right away in the morning. i think a pad might have broke actually. the humming sounds like its coming from the middle rear of the car


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## GM4life (Mar 18, 2007)

Sounds like you may have a clunking and the howling diff. The clunking can sometimes be cured with a fluid change, the howl is alittle more in depth. Does it make the noise during accel or decel? Is the noise constant in a certain MPH or all the time? Any noises in turns?


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## madryan1178 (Sep 28, 2010)

i had the same noise but it was in the front. when i turned to the left the noise got louder and when i turned to the right it went away. it was a wheel bearing. i replaced the hub assembly and it was good to go.


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## sutherlacd27 (Apr 12, 2010)

the humming noise is there at roughly 30 mph and up to any speed. its there during acceleration, deceleration, and while crusing constant. noise goes away with left turns and gets louder with right turns. any idea how much to replace a wheel bearing? i believe they have to be pressed in dont they?


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## Mike_V (Mar 10, 2006)

I think GM4Life is right, and it's your diff. Your symptoms match it exactly.


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## GTO JUDGE (May 14, 2005)

http://www.gtoforum.com/f3/growling-clunking-noise-coming-rear-14102/


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## jpalamar (Jul 22, 2008)

sutherlacd27 said:


> the humming noise is there at roughly 30 mph and up to any speed. its there during acceleration, deceleration, and while crusing constant. noise goes away with left turns and gets louder with right turns. any idea how much to replace a wheel bearing? i believe they have to be pressed in dont they?


I replaced my front wheel bearing from an accidnet and GM wanted $470 I think. Found one online at A1 auto for like $110. 15k or so miles on it so far and no issues.

The more I read I really think its your diff too. Change that fluild out and hope for the best.


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