Perkins v-belts, also known as vee belts or wedge belts T80109108, are designed to prevent slippage and alignment problems. With greater load, the belt will tend to wedge into the groove, providing better performance. Widely used due to the reliability and strength from fiber reinforcement. When replacing fan belts check the belt tension is correct, together with the battery and all the electrical connectors. Where engines have twin belts, check to ensure the belts are of a matched length.