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Rear end noise

srlbotanical

By srlbotanical
in Ask A GM Technician

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srlbotanical Enthusiast

srlbotanical

Posted
Posted

I drive a 97 1500 4x4 silvy 5.7L with the limited slip rear end.

 

When coasting at about 15-20 MPH I can hear a very faint repetitive noise coming from the rear end. It sounds like "wha, wha, wha, wha," but so faint that only I seem to hear it.

 

Now, when I coast around a corner at about 15 MPH it gets louder, but a passanger will not notice it unless I point it out and make them listen closely. I have pulled the back wheels and the brakes are in good shape, I don't notice any fluid leaking from around the seals or anything out of the ordinary.

 

Am I looking at a shaft bearing problem, or somthing else? :)

 

Thanks,

 

Steve

GM-Tech Senior Enthusiast

GM-Tech

Posted
Posted

If the noise changes when you go around a corner, it's unlikely it's a side bearing in the diff. More likely an axle bearing, though weight shifts don't usually change the noise much.

02 Silverado Z71 Enthusiast

02 Silverado Z71

Posted
Posted
I drive a 97 1500 4x4 silvy 5.7L with the limited slip rear end.

 

When coasting at about 15-20 MPH I can hear a very faint repetitive noise coming from the rear end. It sounds like "wha, wha, wha, wha," but so faint that only I seem to hear it.

 

Now, when I coast around a corner at about 15 MPH it gets louder, but a passanger will not notice it unless I point it out and make them listen closely. I have pulled the back wheels and the brakes are in good shape, I don't notice any fluid leaking from around the seals or anything out of the ordinary.

 

Am I looking at a shaft bearing problem, or somthing else?  :)

 

Thanks,

 

Steve

 

 

 

 

 

First of all, make d**n sure you are not hearing any type of tire noise.

Second, when was the last time you changed the rear differential fluid? I'd go ahead and chang it, and also remember to buy the posi-additive from GM.

If none of these tips help, I would say possible a bad pinion bearing? or worn ring and pinion gears? Very tough to tell when you can't hear something in person.

srlbotanical Enthusiast

srlbotanical

Posted
  • Author
Posted

Thanks Guys, I'll change out diff oil first and see what happens. I know its not tire noise, thats the first thing I thought of. I even got in the bed and had my wife drive around so I could hear it better. The only problem was, she didn't drive it exactly the way I wanted, and I ended up having to make my own dinner...

 

Go figure... :)

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