Thanks John, 

I have removed the transmission front cover and have found nothing unusual. After looking further, I found that the coupler between the transmission and bell housing was worn to the point that it was actually hitting the bottom of the belt pulley gear box. This may be the noise I'm hearing. I'm thinking of replacing the coupler itself and hope that it will cure the problem. Any ideas? Also, where would I look for a coupler? 

Thanks again,
Bruce