Removal
Location of markings on the camshaft bearing cap
Location of camshaft bearing caps that need to be unscrewed and removed first
Location of thrust half rings
Removal hydraulic tappets from the cylinder head
1. Set the piston of the first cylinder to TDC and check that all timing marks are aligned with the pointers.
2. Remove the crankshaft sprocket that controls the exhaust valves.
3. Remove the drive chain from the camshaft sprocket that controls the intake valves and use wire to secure the chain from falling.
4. Check for markings on the camshaft bearing caps and, if missing, apply them. The bearing caps of the camshaft that controls the exhaust valves are numbered from 1 to 7 on the drive chain side (see Fig. Location of markings on the camshaft bearing cap), and the bearing caps of the camshaft controlling the intake valves are numbered from 8 to 14 on the drive chain side.
5. Gradually and sequentially unscrew the bolts securing the bearing caps 1, 4, 6 and 7 of the camshaft controlling the exhaust valves and the caps 8, 9, 12 and 14 of the camshaft controlling the intake valves (see Fig. Location of camshaft bearing caps that need to be unscrewed and removed first). Remove the covers.
6. Gradually and consistently, one turn at a time, loosen the bolts securing the remaining camshaft bearing caps. Remove the caps.
7. On 3.0L engines, remove the thrust washers near bearing caps 1, 8, 4 and 11 (see fig. Location of thrust half rings).
8. Remove the camshafts from the cylinder head.
9. Remove the hydraulic valve lifters from their sockets in the cylinder head. Place the hydraulic lifters in a container with clean engine oil in a vertical position so that they can be installed in their places (see fig. Removing hydraulic tappets from the cylinder head).
Examination
1. Check the camshaft bearing surfaces and cam lobe contours for signs of wear. If any wear is present, the camshaft must be replaced.
2. Check the condition of the hydraulic tappets and tappet seats in the cylinder head. If there is wear on the tappet seats, the cylinder head must be replaced.
Installation
Location of camshaft bearing caps that need to be installed first
1. Lubricate the hydraulic lifters with clean engine oil and insert each lifter into its place in the cylinder head.
2. Lubricate the camshaft journals and camshaft lobes with clean engine oil and install the camshafts into the cylinder head.
3. Turn the camshafts to such a position that the cams of cylinder No.2 of the camshaft, which controls the exhaust valves, and the cams of cylinder No.3 of the camshaft, which controls the intake valves, are directed downwards. In this case, the installation holes on the flanges of the camshafts must be aligned with the upper plane of the cylinder head.
4. On 3.0L engines, install thrust washers on bearings 1, 8, 4 and 11.
5. Lubricate the working surfaces of the bearings in the camshaft bearing caps, then install caps 2, 3 and 5 of the camshaft controlling the exhaust valves and caps 10, 11 and 13 of the camshaft controlling the intake valves, and install the bolts in the caps (see Fig. Location of camshaft bearing caps that need to be installed first).
6. Tighten the camshaft bearing cap bolts by hand, then tighten the cap bolts in a spiral pattern from the center outward, turning each bolt one-half turn at a time until each cap contacts the cylinder head. Then tighten the bolts to the specified torque in several stages in the same sequence.
7. Install the remaining camshaft bearing caps and tighten them to the specified torque in the same manner.
8. Install the drive chain onto the camshaft sprocket that controls the intake valves, in accordance with the previously made marks.
9. Install the camshaft sprocket that controls the exhaust valves.
10. Check the original position of the camshafts.