Balance shaft, chain and sprockets — removal and installation
Removal
1. Disconnect the cable from the negative terminal of the battery (see Engine electrical systems).
2. Raise the vehicle and support it securely on jack stands, then refer to Chapter Tune-up and routine maintenance and drain the engine oil and remove the oil filter.
3. Remove the oil pan skid plate if equipped.
4. There is an engine wiring harness at the front of the oil pan. Disconnect the harness bracket.
5. Remove the starter motor (see Engine electrical systems). Also remove the plastic bellhousing side covers (see Automatic transmission). Disconnect the transmission cooler line bracket from the side of the oil pan.
6. Position the number one piston at TDC on the compression stroke (see Top Dead Center (TDC) for number one piston — locating) to align the sprocket timing marks (see illustration 12.14). It may be easiest to wait until you remove the front cover to do this.
7. Remove the oil pump (see Oil pump — removal, inspection and installation).
8. Remove the timing chain cover (see Timing chain and sprockets — removal and installation).
9. Push downwards on the balance shaft thrust plate spring and insert special tool EN-46330 to hold the spring in the down position.
10. Loosen the balance shaft sprocket bolt and the idler shaft sprocket bolt.
11. Remove the balance shaft chain guide retainer bolts and chain guide from the side of the chain.
12. Remove the balance shaft driven sprocket bolt, sprocket and chain as a unit from the camshaft actuator sprocket.
13. Remove the balance shaft retainer mounting bolts and retainer from the front of the engine block.
14. Carefully and slowly pull the balance shaft out. Support the balance shaft near the block so the counterweights don’t nick or gouge the bearings as it’s withdrawn.
Installation
15. Lubricate the balance shaft bearing journals and balance shaft journals with camshaft and lifter assembly lube.
16. Insert the balance shaft retainer on to the end of the balance shaft. Carefully insert the balance shaft into the cylinder block making sure the flat spot of the end of the balance shaft is facing toward the 3 o’clock position.
17. Install the balance shaft retainer bolts and tighten the bolts to the torque listed in this Chapter’s Specifications.
18. Loop the balance shaft chain around the camshaft actuator sprocket, the driven sprocket and the balance shaft idler sprocket.
19. Install the driven sprocket bolt and tighten it by hand.
Caution: The flat spot on the balance shaft must be facing the 3 o’clock position.
20. Check that the timing marks are properly aligned. The lower blue link plate of the balance shaft chain must align with the camshaft actuator triangle mark and the upper blue link plate of the balance shaft chain must align with the dot on the balance shaft driven sprocket (see illustration).
14.20 Balance shaft chain timing mark’s locations
1 Driven sprocket 20th tooth (vertical cast line)
2 Balance shaft driven sprocket timing mark (dot)
3 Balance shaft chain upper plate colored link (blue)
4 Camshaft actuator timing mark (triangle)
5 Balance shaft chain lower plate colored link (blue)
Note: The 20th tooth on the driven sprocket will have a cast-in vertical line pointing at the 12 o’clock position.
21. Place a 0.04-inch (1.1mm) feeler gauge between the balance shaft guide and the chain, then install the bolts and tighten the bolts to the torque listed in this Chapter’s Specifications.
22. Tighten the balance shaft driven sprocket bolt to the torque listed in this Chapter’s Specifications.
23. The idler sprocket should still be able to move up and down. Remove special tool EN-46330 or equivalent from the tensioner
and tighten the idler sprocket bolt to the torque listed in this Chapter’s Specifications.
24. The balance shaft chain should now be tight. If it is, remove the feeler gauge (Step 21) and the chain should now have a slight amount of play.
25. The remainder of installation is the reverse of removal.
26. Add the proper type and quantity of oil (see Tune-up and routine maintenance). Start the engine and check for leaks before placing the vehicle back in service.