I have a 52" rough cut trail cutter swisher pull behind mower that I've had nothing but issues with lately. We just replaced bearings in the mower and put on a new belt & mowed one field just fine. The next time we used it the bearings completely seized up. We again changed them & then went to mow, I got one strip of the field done & boom the blades seized up & mower shut off immediately. The mower starts back up fine but, bearings are seized up so blades aren't able to engage. This is the first time we've ever had this issue with the mower and we've had it for years. I got the bearings directly from swisher. Everything else looks fine, I have no idea what else to do. Any suggestions?