Timing Chain: Service and Repair
TIMING CHAIN AND SPROCKETSREMOVAL
1. Remove the timing chain cover.
2. Remove the camshaft sprocket attaching bolt.
3. Remove the timing chain with camshaft sprocket.
4. Using a suitable puller, remove the crankshaft sprocket. Be careful not to damage the crankshaft surface.
INSPECTION
MEASURING TIMING CHAIN STRETCH
1. Place a scale next to timing chain so that any movement of chain may be measured.
2. Place a torque wrench and socket on camshaft sprocket attaching bolt and apply torque in direction of crankshaft rotation to take up slack; 41 Nm (30 ft. lbs.) with cylinder head installed or 20 Nm (15 ft. lbs.) with cylinder heads removed. With a torque applied to the camshaft sprocket bolt, crankshaft should not be permitted to move. It may be necessary to block crankshaft to prevent rotation.
3. Hold a scale with dimension reading even with edge of a chain link. Apply torque in the reverse direction 41 Nm (30 ft. lbs.) with cylinder heads installed, or 20 Nm (15 ft. lbs.) with cylinder heads removed. Note the amount of chain movement (Fig. 52).
4. If movement exceeds 3.175 mm (1/8 inch), replace timing chain and sprockets.
INSTALLATION
1. Position a new crankshaft sprocket on the crankshaft. Install the sprocket using a suitable tool and mallet. Be sure sprocket is seated into position.
2. Rotate the crankshaft sprocket so the timing mark is at the 12 O'clock position.
3. Place the timing chain around the camshaft sprocket and place the timing mark to the 6 O'clock position.
4. Place the timing chain around crankshaft sprocket and install the camshaft sprocket into position.
5. Using straight edge to check alignment of timing marks (Fig. 53).
6. Install the camshaft sprocket bolt and washer. Tighten the bolt to 74.5 Nm (55 ft. lbs.).
7. Rotate crankshaft 2 revolutions. Timing marks should line up. If timing marks do not line up, remove cam sprocket and realign.
8. Measure camshaft end play. If not within specifications, install new thrust plate.
9. Install timing chain cover.