I had noticed over the past while my x300 seemed to be going a bit slower, yesterday my wife mentioned it had a different sound to it. Any way I have a large ditch on my property and had cut the grass in it multiple times over the past 10 years and no issues. yesterday the tractor would not climb the incline to get out of the ditch. It has 550 hours and engine oil has been change every 50 but have not done anything with rear axle trans since you kind of can't. It did look like there may be a drain and I may be able to top up but not sure. Manual says call dealership. I am open to any suggestions.