Although Ford suggests that this component is removable while the engine is installed in the vehicle, depending on the particular options with which your Aerostar is equipped, working clearance may be extremely tight and this procedure may be much easier to perform with the engine removed. Before commencing, read through this procedure and make certain enough clearance, or working room, exists with the engine in the vehicle; if there is not enough space, the engine should be removed.
REMOVAL & INSTALLATION
See Figures 1, 2 and 3
- Remove the timing belt cover, as described earlier in this section.
- Turn the crankshaft until the crankshaft timing marks and the camshaft timing marks align with those found on the front of the engine block-make sure that ALL of the timing marks are aligned simultaneously, otherwise the internal engine components will not correctly positioned. The engine should be at Top Dead Center (TDC) when these marks are aligned.
- Remove the crankshaft pulley and belt guide.
- Loosen the belt tensioner pulley assembly, then position a camshaft belt adjuster tool (T74P-6254-A or equivalent) on the tension spring rollpin and retract the belt tensioner away from the timing belt. Tighten the adjustment bolt to lock the tensioner in the retracted position.
- Remove the timing belt.
- Install the new belt over the crankshaft sprocket and then counterclockwise over the auxiliary and camshaft sprockets, making sure the lugs on the belt properly engage the sprocket teeth on the pulleys. Be careful not to rotate the pulleys when installing the belt.
- Release the timing belt tensioner pulley, allowing the tensioner to take up the belt slack. If the spring does not have enough tension to move the roller against the belt (belt hangs loose), it might be necessary to manually push the roller against the belt and tighten the bolt.
The spring cannot be used to set belt tension; a wrench must be used on the tensioner assembly.
- Rotate the crankshaft two complete turns by hand (in the normal direction of rotation) to remove the slack from the belt, then tighten the tensioner adjustment and pivot bolts to specifications. Make sure the belt is seated properly on the pulleys and that the timing marks are still in alignment when No. 1 cylinder is again at TDC/compression.
- Install the crankshaft pulley and belt guide.
- Install the timing belt cover, as described earlier in this section.