Starting around 75 hours I started to have an issue with my steering. Turning the wheel it would make a thump feel and you could see the front tires jerk when it was either turned around the 10 o'clock or 2 o'clock position. Also if you turned the steering wheel in either direction slowly the wheels wouldn't move unless it was turned fast. This would happen when the tractor has been running for a least an hour and a half getting the fluid nice and warm. Took it to the dealer at 100 hours and they determined it was the steering valve below the steering wheel. They replaced it and was fine for three weeks and today it's back doing the same thing but also now has a squeal/wine sound around 90% turn of the steering wheel left or right and can feel both hoses going to the front steering cylinder vibrate when it squeals/wines. Fluid level is full. I'm really scratching my head on this one. Any ideas? I'm wondering if a clogged hydraulic filter would cause this but have no other hydraulic issues. Filter was changed at 50 hours. Like I mentioned above, it really seems to show when the fluid is hot like when I've been mowing for awhile. Also today when I was mowing I was turning the steering wheel at a normal speed and a few times the tires didn't turn.