Timing belt - inspection, removal and refitting
Inspection
1 This operation will only normally be required at the specified timing belt renewal intervals (see Chapter 1), or for removal of the coolant pump.
2 Disconnect the battery earth lead.
3 Release the alternator mounting and adjuster link bolts, push the alternator in towards the engine and slip the drivebelt from the pulleys.
4 On earlier models, unscrew the four retaining bolts and remove the timing belt cover.
Undo the four retaining bolts (arrowed) to remove the timing cover - 1-piece
type
Note that a two-piece cover has been progressively introduced on all later models.
The 2-piece timing belt cover
The upper half of the cover is visually similar to the earlier one-piece type and can be removed after undoing the two retaining bolts. To withdraw the lower half it will first be necessary to remove the crankshaft pulley after which the two retaining bolts can then be undone and the cover removed.
5 The timing belt can now be inspected for signs of excessive wear or damage; if found, the belt must be renewed. If the belt is damaged or has worn prematurely, a check must be made to find the cause. There are three main causes of timing belt failures and these are as follows:
a) If some of the teeth have sheared off and some are badly worn, check the surface of the crankshaft pulley teeth for signs of damage or defects and renew the pulley, if necessary.
b) If some belt teeth have sheared off and others are cracked at their roots, then this indicates an excessive torque loading on the belt, and the water pump, distributor, timing belt tensioner wheel and the camshaft must be checked for freedom of movement. In the case of the camshaft the rockers must be removed when checking it for freedom of rotation. Renew or repair as necessary before renewing the timing belt.
c) If some teeth have sheared from the belt whilst others are undamaged, the belt will have jammed in the belt pulley or the engine has possibly been over-revved. Check the items mentioned in (b) and renew as necessary.
Note: In 1988, an improved timing belt was introduced (part no. 1653887) together with a modified tensioner pulley of larger diameter (part no. 6182891). If the belt is to be renewed, then the modified pulley must also be renewed.
Removal
6 To remove the timing belt, proceed as follows:
7 Using a ring or socket spanner on the crankshaft pulley bolt, turn the crankshaft until the timing mark on the camshaft sprocket is opposite the TDC mark on the cylinder head and the small projection on the crankshaft belt sprocket front flange is in alignment with the TDC mark on the oil pump casing. Remove the starter, jam the flywheel ring gear and unbolt and remove the crankshaft pulley.
Camshaft sprocket timing mark
Align the crankshaft sprocket with its timing mark
One method of jamming the flywheel ring gear . . .
. . . another method of jamming the flywheel ring gear
8 Slacken the bolts which secure the belt tensioner and using a large screwdriver, prise the tensioner to one side to relieve spring tension on the belt. (Some tensioners do not incorporate a spring.)Temporarily retighten the bolts.
9 If the original belt is to be refitted, mark it for direction of travel and also the exact tooth positions on all three sprockets.
10 Slip the timing belt from its sprockets.
Refitting
11 Refit by reversing the removal operations, but before engaging the belt to the camshaft and crankshaft sprockets, check that they are set to TDC as previously described. Adjust the position of the sprockets slightly if necessary, but avoid any excessive movement of the sprockets while the belt is off, as the piston crowns and valve heads may make contact, with consequent damage to both components.
12 Engage the timing belt with the teeth of the crankshaft sprocket (slip the sprocket off the crankshaft if necessary to avoid kinking the belt), and then pull the belt vertically upright on its right-hand run. Keep it taut and engage it with the teeth of the camshaft sprocket. Check that the positions of the crankshaft and camshaft sprockets have not altered.
13 Wind the belt around the camshaft sprocket, around and under the tensioner idler pulley and over the coolant pump sprocket (no set position for this).
Timing belt correctly located
14 Loosen the tensioner retaining bolts by half a turn each to allow the tensioner to snap into position against the timing belt.
15 With the crankshaft locked in position at TDC, fit a 41 mm socket and torque wrench onto the camshaft sprocket hexagon and apply an anti-clockwise torque in accordance with the settings given in the Specifications. Whilst applying this torque setting to the camshaft, simultaneously tighten the tensioner retaining bolts, right-hand then lefthand bolt, to their specified torque wrench setting. This is an initial setting up procedure only - the belt tension should be checked with Ford tool 21-113: therefore the car will have to be taken to a dealer as soon as possible.
Method used to initially tension the timing belt
16 Refit the crankshaft pulley, the retaining bolt and washer, and tighten to the specified torque wrench setting.
Crankshaft pulley, bolt and washer
17 Refit the belt cover, refit and adjust the drivebelt, and reconnect the battery.