If you have 4x4 engaged, the braking force of the front wheels might make it tilt forward even more quickly. You completely change the physics of the tractor when you put that much weight out in front of the front wheels, never mind the front axle turns into a seesaw once the back wheels are off the ground. Keep that bucket as low as possible when moving, even empty, and even if it occasionally rubs the high spots in your road. You'll only smooth your road some as you work, and you'll minimize the seesaw effect of the front axle pivot. If a load in the bucket or lifting on something with the FEL can raise the back wheels, even slightly, you need more counterweight on the back of the tractor. The hydraulic system of your tractor is designed to prevent you from damaging the "suspension" (pivot pin in the front axle) or breaking the front axle. It will relieve the pressure if the load is too much for the FEL (and the weight limits of the tractor). The rear axle and tires are clearly stronger and can be loaded up heavily to counterbalance the front loading. If you're doing loader work, put your heaviest 3-point attachment on the back. If you have none (yet), get an old drum and outfit it for a 3-point connection to the tractor, and fill it full of ballast be it rocks, concrete, whatever. The farther back you can put the ballast, the more effective it is, but then you start getting into overall length and maneuverability issues. Just get something heavy on the back.