You'll need to install a tension pulley for a Ford Bronco when the Bronco’s engine is running but the accessories are not. Turned by a single serpentine belt, a Bronco’s alternator, power steering, water pump and air conditioner are affected if the drive belt comes loose. The tension pulley stretches a Bronco’s serpentine belt so it will continue to charge the battery, cool the air and make it easier to steer. These steps can be used to guide you through the project when your Bronco’s tension pulley needs to be replaced.
Park the Ford Bronco on a flat surface and engage the parking brake. Exit the vehicle and raise the hood. Disconnect the battery so that all the accessories are not charged with electricity. Remove the positive (red) cable from the positive battery post and store the cable away from the battery when you install a tension pulley for a Ford Bronco.
Locate the tension pulley. It is on the passenger front side of the engine at the top of the serpentine belt, to the right of the alternator. It is held in place by and armature, and the serpentine belt runs under the pulley. Push on the belt that goes around the pulley to see if there is slack enough in the belt to remove it from the pulley without loosening it first. If the belt is too tight to remove, use a wrench to loosen the center retaining bolt of the pulley. The pulley will loosen and the belt can be freed from the grooves of the pulley
Loosen the retaining bolt in the center of the upper arm that connects the tension pulley assembly to the engine block. Turn the bolt counter-clockwise until the arm comes free from the engine and the entire assembly, tension pulley and arm come free from the motor.
Disassemble the tension pulley assembly at the pulley. Remove the tension pulley by removing its center retaining bolt. Replace the worn pulley with a new one and secure it to the tension assembly using the existing tension pulley retaining bolt through the center of the pulley. Tighten it to 30 foot-pounds of torque before securing the tension assembly back on the engine.
Secure the tension pulley assembly to the engine using the armature retaining bolt and tighten to 30 foot-pounds of torque. Pull the Ford Bronco’s serpentine belt over the tension pulley with the tension pulley still loosely bolted to the tension assembly arm. Tighten the center retaining bolt of the tension pulley after the belt is run around the tension pulley. Tighten until the belt and the tension pulley are tight enough to spin the accessory drive pulleys when the engine is running.
