I was mowing my 4 acre yard a few weeks ago and suddenly lost all hydraulic power. No forward, reverse, steering or mower lift. I read all the posts here and found one by SLIM back in February that had a similar problem with a failed gerotor in the pump. Sure enough I pulled the pump apart and found the gerotor in little pieces. I checked the INTERNET and found this part available in several places. I ordered the part and now just waiting for it's arrival. Since this part is so readily available I'm thinking this must be a common problem with this type of drive unit. Anyone have any thoughts of what would cause this to fail and how to prevent it. There was alot of crud around the unit when I pulled the seat and rear cover off. I had not checked the fluid level in a while but it was full when it failed. I was at the 300 hour mark so it was ready for a filter & fluid change that I have been procrastinating over. It's an easy fix once you know what's wrong. Thanks To SLIM I was able to go right to the problem. Sharing problems & fixes is what this Forum is about.