My 100 makes a lot of growling in the transmission. I have an A and BN so I know about what normal transmission noise is on these tractors and the 100 is a lot louder. There no noise when its not moving and its louder in higher gears. I'm getting ready to split the tractor to put an oil seal at the transmission so I'm thinking its a good time to look for any other problem. There is no metal in the transmission as I had the PTO out last year to change that seal so you can see the bottom of the transmission real well at that point. Amy suggestions as to what to look for or maybe I don't have a problem.