Camshaft Gear/Sprocket: Service and Repair

REMOVAL - CAMSHAFT SPROCKETS

CAUTION: The 3.2/3.5L engines are NOT a freewheeling design. Therefore, care should be taken not to rotate the camshafts or crankshaft with the timing belt removed.

CAUTION: When camshaft sprocket bolts are loosened or removed, the camshafts must be re-timed to the engine. Also, the camshaft sprocket bolts must NOT be reused.

1. Remove front timing belt covers.





2. Position crankshaft sprocket to the TDC mark on the oil pump housing by turning crankshaft in the clockwise direction (Fig. 147).





3. Install a dial indicator in number 1 cylinder to check TDC of the piston (Fig. 148). Rotate the crankshaft until the piston is at exactly TDC.
4. Remove camshaft retainer/thrust plates from rear of cylinder heads. To access the right side plate, remove the EGR valve.

NOTE: Special Tool 6642 is interchangeable between cylinder banks.





5. Install Special Tools 6642 Camshaft Alignment tools to the rear of each cylinder head by inserting pin on the alignment tool to the pilot hole on the camshaft. Attach tools using the retainer plate bolts. (Fig. 149).

NOTE: If the alignment tools do not properly line-up to install attaching bolts, first remove the timing belt tensioner, then slowly rotate camshaft with a wrench until bolts can be installed.

6. Remove the timing belt.
7. Hold camshaft sprocket with 36 mm (1 7/16 in.) box end wrench.
8. Loosen and remove bolt and washer. To remove the camshaft sprocket bolts with engine in the vehicle, it may be necessary to lift the engine to allow bolt removal clearance. The right bolt is 213 mm (8 3/8 in.) long and the left bolt is 255 mm (10.0 in.) long.

NOTE: Each sprocket has a "D" shaped hole that allows it to rotate several degrees in each direction on its shaft. This design requires the crankshaft-to-camshaft to be properly timed to ensure proper engine performance.

9. Remove the camshaft sprockets.




INSTALLATION - CAMSHAFT SPROCKETS





CAUTION: The camshaft sprockets are not interchangeable from side to side (Fig. 153).





1. Install camshaft sprockets onto the camshafts. Install NEW sprocket attaching bolts into place. The 255 mm (10 in.) bolt is to be installed in the left camshaft and the 213 mm (8 3/8 in.) bolt is to be installed into the right camshaft. Do not tighten the bolts; tightened at later step. Camshaft sprocket mark should be positioned between the marks on the cover at both sprockets (Fig. 154).





2. Install the timing belt starting first at the crankshaft sprocket, then to remaining components in a counterclockwise direction (Fig. 155).
3. Install the belt around the last sprocket. Maintain tension on the belt as it is positioned around the tensioner pulley. Each camshaft sprockets mark should still fall between the cover marks (Fig. 155).

NOTE: For timing belt tensioner reset procedure, Refer to TIMING BELT - REMOVAL.

4. Hold the tensioner pulley against the belt and install the reset (pinned) timing belt tensioner into the housing. Tighten attaching bolts to 28 Nm (250 in. lbs.).
5. Remove tensioner retaining pin to allow the tensioner to extend to the pulley bracket.





6. Using a dial indicator, position the number 1 piston at TDC (Fig. 156).
7. Hold the camshaft sprocket hex with a 36 mm (1 7/16 in.) wrench and tighten the camshaft bolts to the following:
- Right side = 102 Nm (75 ft. lbs.) +90° turn
- Left side = 115 Nm (85 ft. lbs.) +90° turn
8. Remove dial indicator and install spark plug.
9. Remove Special Tools 6642.





10. Install cam retainer/thrust plates and O-rings (Fig. 157). Tighten bolts to 28 Nm (250 in. lbs.).
11. Install timing belt covers.
12. Install crankshaft vibration damper.
13. Install accessory drive belts.
14. Fill cooling system.