Timing Chain: Service and Repair

^ Tools Required
- J 7872 Magnetic Base Dial Indicator

Removal Procedure





1. Remove the engine front cover.
2. Attach the J 7872 to the front of the engine cylinder block. Position the magnetic base dial indicator to allow the plunger to contact the timing chain.
The magnetic base dial indicator plunger should contact the timing chain centered between the two sprockets.
3. Using finger pressure on the inside radius of the timing chain, push the timing chain outward (parallel to the front face of the block) to the maximum deflection.
4. Set the J 7872 to zero.
5. Using finger pressure on the outside radius of the timing chain, push the timing chain inward (parallel to the front face of the block) to the maximum deflection.
6. Note the deflection of the timing chain (total travel of the magnetic base dial indicator plunger).
^ For used parts, the deflection must not exceed 20.3 mm (0.80 inch).
^ For new parts, the deflection must not exceed 12.7 mm (0.50 inch).
7. If the deflection exceeds the limit, replace the worn parts.





8. Remove the bolt from the timing chain sprocket to the camshaft.





9. Remove the fuel injection pump drive gear from the timing chain sprocket.





10. Remove the timing chain and sprocket from the camshaft.





11. Remove the sprocket from the crankshaft.

Important: Replace the timing chain sprocket key if there are signs of excessive wear or damage. Do not try to repair the key.

12. Inspect the timing chain sprocket key.
13. Inspect the crankshaft gear key for damage.
14. Replace the keys if damage is found.

Installation Procedure





1. Install the key in the crankshaft, if removed.
2. Install the key in the camshaft, if removed.

Important: Do not damage the reluctor wheel square bosses.

3. Install the crankshaft sprocket with the reluctor wheel square bosses facing the front to the crankshaft.





4. Align the timing marks.





5. Install the camshaft sprocket with the timing chain.





Notice: Refer to Fastener Notice in Service Precautions.

6. Install the timing chain sprocket bolt to the camshaft.
^ Tighten the bolt to 170 Nm (125 ft. lbs.).
7. Perform steps 2 through 6 of the removal procedure to measure the timing chain deflection.
8. Install the engine front cover to the engine block.

Notice: Perform TDC Offset Recovery procedure if the timing chain, timing gears, engine front cover, crankshaft position sensor, crankshaft or other components affecting the timing are replaced.

9. Perform TDC offset timing adjustment.