Candidly, it seems a part of the problem is that you don't fully grasp the inter-relatedness of all these things...the front tires, the loader (which has weight even empty), the rear tires. I don't say this to be nasty, but that's the conclusion I've come to. Your responses are getting a bit sharp from where I sit.....folks are just trying to help you, and some solid information has been posted. Take some time and try to digest all of it. Imagine your tractor with the bucket a foot off the ground. Any force on the bucket (such as the weight of the loader even) pushes down, the front axle/tires serve as a fulcrum, and this force has a lifting effect on the rear of the tractor, reducing the weight on the rear tires, thus reducing traction. Add to that the additional pressure on the front tires pushing them INTO the ground, making it harder to push them forward. An empty loader can be enough on a small tractor in loose footing (such as sand). Fix the physics of the situation.