I would check the cam bearings and rollers on pickup , then check to see if there was any slack in the packer arms. I run 4910's , I go thru them every spring before season starts , change anything that they might need ? I am lucky to have a baler tech less than a hour away that comes here to help , which is great , he has shown me many things that I didnt know about working on them. I know of some very high bale counts on some balers and that dont seem to matter long as they were maintained properly. Check all the cluthes for slack or loose parts,twine rollers and followers they should roll easy and not bind up. Needle rollers too, make sure needle arms are not bent or sprung . What I know about the 4x4 balers they seem to be very dependable , never ran a 3x4 . I bale several thousand bales each season and dont have too many problems. Make sure that you get 1 that has a lincon AUTO-LUBE on it that is a very important item besides a good BLOWER . They are a must to have on a big baler.