If your rear gear is going bad, what does it feel like when you are on the track?

Thanks for the response.  that doesn't sound like my issue.

I sounded like something was hitting my floor board.  Randomnly during wheel pack and then when I got off the gas, going into the corner during hot laps.  I couldn't dublicate it in the pits with the rear wheels off the ground.

I made sure the crossmember, trans mount, engine mounts were all tight.  I looked to see if the drive shaft was hitting the tunnel.  I couldn't find anything.  

I few laps later my timing chain broke.  But I can't imagine how that problem would cause the noise.

CD