I have an Exmark Lazer Z HP 52in 27hp Kohler. I started the season by having to replace both drve motor spindles and wheel hubs. The key in the spindle had somehow rolled and the keyway was wallowed really bad. Fixed under warranty and two months later I can feel it doing it again...???? anyone else have any issues with this? The mower is less than 2 years old, not sure of hours b/c I thing the hr meter has malfunctioned.