Axle Question

[mnetwork]

I put in my new Autozone driver side axle today and it had something on it that my original one didn't have. For all I know the axle in there could be the original axle. The new one I got has a rubber boot type thing around the middle of it. I found a picture of what I am talking about....

I am just curious, can someone tell me what this?

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[cheap90gsx]

I asked the same thing to the store i bought a drive line from and he said it was to balance it. although, the rubber piece was on my old one and he said the new one was designed different.

 

[->PrOjEcTGS<-]

It's a rubber dynamic damper. It's there to dampen any excessive vibrations that are caused by the shaft. Just like a harmonic damper works on the front of the engine.

 

[mnetwork]

Ohh, makes sense. Thanks for the answers.