What is this thing on my muffler?

[BradB]

Just looking over my 'new-to-me' '97 4Runner and saw this odd protuberance. Just hanging in mid air on a bracket. Figured most everyone else knows what this is.

 

[Dous]

I believe it is supposed to stop vibrations from the exhaust.

 

[BradB]

Really? That's interesting. Thanks!

 

[Koz]

It helps to eliminate exhaust drone noise!

Koz

 

[badattitude]

It's called a harmonic dampener. It reduces noise and vibration.

 

[BradB]

Gee, and I thought it was just a lump of rubber! Thanks guys.