If your snowblower isn't clearing pavement well, first turn off the snowblower and clear any snow that's built up in the chute. A clogged chute won't throw snow very far.
If the chute isn't clogged, check the augers and auger drive system. A damaged auger blade can't push snow through the shoot, and broken shear pins keep sections of the auger from spinning. A worn, stretched auger belt won't spin the auger fast enough to throw snow off the pavement, so replace the auger belt if it's worn. If the belt is okay but the cable isn't keeping the belt snug on the pulleys, adjust the auger drive cable. A broken gear case can also prevent the augers from spinning at the right speed, so replace the gear case if the auger shaft doesn't spin at the right speed.
If you didn't tune up the snowblower at the start of the season, the engine might be running rough and lack the power to throw snow. And if the chute doesn't pivot, you could end up blowing snow into the wind-and right back onto the driveway. Repair or replace the chute control assembly so the chute pivots. If your snowblower has a 4-way chute control, repair or replace that control if you're not able to control the chute. Adjust or replace the chute deflector cable if it isn't controlling the chute.
These videos also offer tips on why a snowblower won't throw snow.
