Primary Chain

Note: These engines have an interference fit design. If engine has jumped time, damage will result to cylinder, valve and piston assemblies.

CAUTION: At no time, when the timing chains are removed and the cylinder heads are installed, may the crankshaft and/or camshaft be rotated unless all rocker arms have been removed. Rotation may result in valve and/or piston damage. Before loosening or tightening camshaft sprocket nuts and bolts, ensure camshaft positioning and locking devices are in place.

REMOVAL
1. Remove engine from vehicle.
2. Remove valve covers.
3. Remove rocker arms.
4. Remove front engine cover.

Fig. 17 Setting Engine To TDC Of No. 1 Cylinder:

5. Remove crankshaft position pulse wheel, then rotate engine to No. 1 TDC.

Fig. 18 Camshaft Positioning Tool Installation:

Fig. 24 Camshaft Holding Tool:

6. Install camshaft positioning tool T93P-6256-A, and camshaft holding tool T93P-6256-AH, or equivalents, to camshafts.
7. Remove righthand tensioner attaching bolts, then remove tensioner and arm.
8. Remove righthand chain guide attaching bolts, then remove chain guide. Note length of bolts for installation.
9. Remove righthand timing chain, then remove righthand crankshaft sprocket. Note position of sprocket for installation.
10. Remove righthand camshaft gear attaching bolt, washer, and gear, if required.
11. Remove lefthand tensioner attaching bolts, then remove tensioner and arm.
12. Remove lefthand chain guide attaching bolts, then remove chain guide. Note length of bolts for later installation.
13. Remove lefthand timing chain, then remove lefthand crankshaft sprocket. Note position of gear for later installation.
14. Remove lefthand camshaft gear attaching bolt, washer, and sprocket, if required.

INSTALLATION

CAUTION: If engine has jumped time, ensure all repairs to engine components and/or valve train are completed. During timing chain installation ensure all rocker arm have been remove, if cam or crank should turn with rockers installed engine damage will result.

1. Rotate engine until keyway is 45° counterclockwise from vertical.
2. Ensure secondary timing chain and tensioner are correctly installed.
3. Install camshaft positioning tool T93P-6256-A, and camshaft holding tool T93P-6256-AH, or equivalents, to camshafts.
4. If removed, install primary timing chain cam sprockets onto camshaft. Tighten nuts finger tight at this time.

Fig. 25 Crankshaft To Camshaft Timing:

5. Install lefthand timing chain onto camshaft sprocket, ensure one of the colored links of timing chain is aligned with timing marks of camshaft sprocket.

Fig. 26 Crankshaft Sprocket Position:

6. Install left timing chain onto crankshaft sprocket. Ensure one of the colored links of timing chain is aligned with timing marks of crankshaft sprocket. Ensure tapered boss of crankshaft sprocket is facing away from engine block.
7. Bleed timing chain tensioner.
8. Install left chain rail, tensioner and arm.
9. Using a suitable C-clamp across both timing chain rails, remove all slack from timing chain, then release timing chain tensioner.
10. Repeat above procedures for right timing chain, note that crank shaft sprocket tapered boss faces towards engine block.
11. Tighten camshaft sprockets.
12. Install crankshaft position pulse wheel.
13. Install front engine cover.
14. Install rocker arms.
15. Install valve covers.
16. Install engine into chassis.