2013 Toro MX5060. 270 hours. Drive belt was replaced at the shop 2 months ago. The mower drifts to the left when mowing full speed. I can mow with it easy enough. Its just that I have to pull back the right bar slightly to mow straight. Also, I notice that when sitting still if I move the left control bar and then let go of it it goes back to neutral position. The right control bar does not; it stays about where I turned loose of it. It seems the left side has what I'd call the spongy feel -- like a hydraulic pressure feel-- which is what I'd think it should have. The right control bar doesn't have that feel. It just moves back and forth with my hand movements and the mower responds; but there is no little resistance there. I'm not a lawnmower repair man --l don't know if I'm describing this properly. Again, I can mow with it but one side just feels different than the other. Trans oil has never been changed, which I asked two different Toro dealers about that, they both said forget about doing that till 500 hours.