Vermeer 504 super i baler bogging

I have a vermeer 504 super I. First cutting this year it baled perfect. I found a bad bearing on the starting roller and replaced it. When I started baling again it runs smooth and quiet. When bale gets between 4 and 5 feet the baler pulls the tractor down and starts squeling. I can't figure out where the squealing is coming from and i cant find anything that seems wrong. Any ideals?

Vermeer 504 super i baler bogging