Timing Belt: Service and Repair

Fig. 13 Timing Belt Removal:

Fig. 14 Camshaft & Crankshaft Sprocket Timing Marks:

REMOVAL

1. Remove battery ground cable.
2. Disconnect breather and secondary air hoses, then remove air cleaner assembly, air intake duct and heated air duct as needed.
3. Disconnect accelerator cable and oxygen sensor lead, and remove spark plug wires as needed.
4. Remove accessory drive belts.
5. Support engine as needed, then remove left engine mount bracket.
6. Remove power steering pump, if equipped and water pump pulleys.
7. Remove rocker arm cover, gasket and packing, and the upper timing belt cover.
8. On 1991-92 models, using special tool No. MD998747 and discarded drive belt, stop rotation of crankshaft pulley, remove A/C and crankshaft pulley, Fig. 13.
9. On all models, rotate crankshaft in normal direction of rotation (clockwise) until timing marks are aligned, Fig. 14, loosen belt tensioner bolts and move timing belt tensioner fully toward the water pump, then tighten bolts to hold tensioner.
10. Remove timing belt. If the timing belt is to be reused, place an arrow mark indicating turning direction (direction of engine rotation) to ensure the belt is installed in the same direction as before.
11. Remove camshaft sprocket, crankshaft sprocket and flange, and timing belt tensioner as needed.
12. Inspect belt and replace if any of the following conditions are noted:
a. Hardened back surface rubber. With back surface glossy, non-elastic and so hard that no mark is produced when fingernail is forced into surface.
b. Cracked back surface rubber.
c. Cracked or separated canvas.
d. Cracks at tooth bottom or side of belt.

Fig. 15 Installing Flange & Crankshaft Sprocket:

Fig. 16 Checking Timing Belt Tension:

INSTALLATION

1. Install flange and crankshaft sprocket as shown in Fig. 15.
2. Tighten crankshaft sprocket bolt.
3. Install camshaft sprocket.
4. Install timing belt tensioner as follows:
a. Mount tensioner, spring and spacer, then temporarily tighten pivot bolt.
b. Temporarily tighten the adjusting bolt, then install bottom end of the spring into front case.
c. Secure tensioner to the position nearest the water pump.
5. Ensure timing marks are aligned, Fig. 14.
6. Install timing belt over crankshaft sprocket, then the camshaft sprocket, keeping tension side of belt tight as belt is installed. If used belt is installed, ensure belt is installed in original direction.
7. Apply counterclockwise force to camshaft sprocket to tighten tension side of belt, ensuring that timing marks remain aligned.
8. Install crankshaft pulley to prevent belt from slipping off sprocket, then adjust belt tension as follows:
a. Loosen tensioner bolts to allow tensioner to bear against belt, then tighten adjusting bolt and pivot bolt. Tighten adjusting bolt first to prevent tensioner from rotating away from belt.
b. Rotate crankshaft clockwise one full revolution, then realign crankshaft sprocket timing mark with pointer. Crankshaft must be rotated smoothly, in clockwise direction. Do not apply any force other than spring force of tensioner to timing belt.
c. Loosen tensioner pivot and adjusting bolts. then tighten adjuster bolt and pivot bolt. Tighten adjusting bolt first to prevent tensioner from rotating away from belt.
d. Check belt tension by holding belt as shown in Fig. 16, and applying thumb pressure to tension side of belt. Tension is correct when tooth of belt covers approximately 1/4 the width of the tensioner adjuster bolt.
e. Rotate crankshaft clockwise, one full revolution and ensure timing marks line up.
9. Reverse remaining procedure to complete installation, then adjust valve clearances as outlined.