Strange Noise

[sprindle]

I have an unusual noise coming from the back of my 2000 Blazer I need some help with. After the vehicle has been driven for a while I get a buzzing sound coming from the rear axel area. This is an intermittent buzzing almost like the exhaust was rattling on the axel. I've checked the clearance and everything is secure and in place. Anyone have any ideas here?

[BlazerLT]

Can you be more specific on the noise.

Metal on metal?

[sprindle]

Yep, it's almost like a metal against metal buzzing. It does subside when RPMs are raised and sustained. The Buzzing is usually at the low RPM when I first raise the RPM.

[BlazerLT]

Cat Convertor.

[JParrott]

Had a problem similar a couple years back....ended up being a baffle inside the muffler had come loose/broken off. Fixed under warranty, so no skin off my back other than inconvienience.