John Deere 467 problems

I have a John Deere 467 with around 14000 bales on it. Last year is started making a bumping noise it in. I comes an goes thru out the day. I have replaced all my big bearing on the outside of Baler an in the process of changing the inner roller bearing. I have tore the pickup apart an it all looks good. It sound like it coming out of the top of the Baler, but it hard to pin down. Any suggestions? Thanks

John Deere 467 problems