Note: The slack of the camshaft drive chain increases with its wear. The following will describe a method for checking the chain without disassembling the engine.
Checking the camshaft drive chain deflection
For 3.0L engines
1. Disconnect the negative battery cable.
2. Remove the front valve cover (section 3).
3. Loosen the exhaust valve lever bolt for cylinder #5 (center). This is the fourth valve lever on the left side of the engine (drive belt side). Turn the valve lever.
For 3.8L engines only
4. Remove the rear valve cover (section 3).
5. Loosen the exhaust valve lever bolt of cylinder No.3. Turn the valve lever.
For all engines
6. Attach a dial indicator to the end of the push rod (see illustration).
7. Turn the crankshaft clockwise to the TDC position (section 11) This will allow you to take up the slack on the right side of the chain (see picture).
8. Set the indicator to zero.
9. Slowly turn the crankshaft counterclockwise until you notice the movement of the arrow on the indicator (see figure). Stop and look at the adjustment marks to determine the angle of deviation from TDC.
10. If the value reaches 6 degrees, replace the camshaft drive target and sprockets.
Removal
11. Set piston No.1 to TDC (section 11).
12. Remove the camshaft drive chain cover (section 10). When removing the shock absorber, do not move the crankshaft.
13. Check that the marks on the upper and lower chain sprockets match (see figure). If they do not match, screw in the vibration damper bolt and use it to turn the crankshaft clockwise until the marks match on the same line.
14. Remove the bolt securing the camshaft sprocket (see figure) and, for 3.8L only, the distributor gear (see figure).
15. Remove the camshaft sprocket from the engine and slide it down slightly to release the chain from the crankshaft sprocket.
16. If the crankshaft sprocket cannot be removed by hand, carefully pry it off with two screwdrivers.
17. The 3.8L engines are equipped with a balance shaft. It is not necessary to remove the balance shaft gear to remove the camshaft drive chain. However, if greater access to the camshaft is required, note the location of the adjustment marks on the balance shaft and subsequently install the gears according to them.
Installation
18. Install the crankshaft sprocket (see illustration), making sure the keyway and adjustment mark are at the top (12 o'clock position).
19. If the sprocket is difficult to move, place the extension tube on the shaft and tap the sprocket into place using a small hammer. Make sure the keyway is not warped.
20. Pull the chain onto the camshaft sprocket so that the adjustment mark is exactly at the bottom (6 o'clock position). Place the chain onto the crankshaft sprocket and place the camshaft sprocket onto the camshaft.
21. In this position, the adjustment marks should be adjacent (the camshaft sprocket mark is at 6 o"clock, and the crankshaft sprocket mark is at 12 o"clock), (see figure).
Caution: Incorrect installation and adjustment may cause serious engine damage.
22. Install the timing gear (3.8L engines only) and tighten the camshaft sprocket bolt to specification.
23. Reassemble the remaining parts in the reverse order of disassembly. Make sure the spring and axial load button (early 3.8L models) are properly installed and well lubricated.
24. Add oil and coolant if necessary, start the engine, check for leaks.