Ford started production of the Ford Focus in 1999. The models made from 1999 to 2007 were the first generation of this series. The standard engine in the 2003 Focus has four cylinders and a displacement of 2.0 litres. The timing belt on this vehicle synchronises the movements between the crankshaft and the camshaft. The tension on the timing belt is a critical factor in its installation.
Open the bonnet. Disconnect the negative battery terminal with socket wrench. Turn the drive belt tensioner clockwise to reduce the tension on the accessory drive belt. Remove the drive belt. Disconnect the tensioner with a socket wrench. Remove the timing belt cover.
Raise and support the vehicle on jack stands. Remove the right front wheel with a lug wrench and disconnect the right splash shield. Remove the pulley for the crankshaft.
Turn the crankshaft clockwise to align the timing marks on the crankshaft and camshaft sprockets. Loosen the tensioner bolt on the timing belt with a socket wrench. Turn the tensioner counterclockwise by 1/4 turn with an 8mm Allen wrench. Place a 1/8-inch drill bit into the hole on the timing belt tensioner to hold the belt tensioner in place. Remove the timing belt.
Install the new timing belt onto the crankshaft by proceeding in a counterclockwise direction. Remove the drill bit from the hole in the timing belt tensioner. Turn the crankshaft clockwise by two turns so that the timing marks align once again. Torque the tensioner bolt for the timing belt to between 15 and 22 foot-pounds with a torque wrench.
Install the crankshaft pulley with a socket wrench and tighten its mounting bolt to between 81 and 96 foot-pounds. Connect the right splash shield and the right front wheel. Lower the vehicle and replace the timing belt cover. Install the accessory drive belt tensioner and mount the drive belt. Attach the cable to the negative battery terminal.