When I was a dealer, the F900 series had issues with the steer axle pivot. The axle was plenty stout but it pivoted on a 5/8"(?)bolt which would eat up the bushings pretty quickly, especially with a bagger. Later models went to a trunion bearing to solve this issue, which is what we suggested to the engineers years ago. Power steering cylinders were also common. Also, there were a couple brackets on the PTO assy that would fatigue and break, and micro-switches on the hydro pedals that were finicky. Don't take this as bashing, by the way, they are a good machine, with a Yanmar diesel that I'd put on par with a Kubota. Commercial service will find the breaking point of any machine.