Hello everyone, we have a old gray model 5409 disc mower and the last several years it has been giving us a lot of problems in the second and third pod. The upper bearings have went out a couple times within a hour of replacing them. After that happening we took the pods apart pulled the shaft out and replaced bearings that go around the shaft and we thought that had fixed our problem. We were able to use it for 40 or 50 acres last year and things seem to be fine. This year within using it for 30 minutes the four hex screws that hold the hub to the housing worked loose and the whole turtle came off the third pod.. luckily the bearings seemed fine. We got new shims and screws and put it back together with loctite and today it did fine but now the second pod screws have worked loose. luckily we caught it before all four came out. We called the dealership and they said we just needed to tighten those screws back down with loctite, but we are thinking surely there is something going on causing vibration and them to work loose. Does anyone have any insight as to what might be causing this.