Timing Chain and Sprocket

TIMING CHAIN AND SPROCKETS

TOOLS REQUIRED:
- J 23444-A Crankshaft Sprocket Remover
- J 38612 Crankshaft Sprocket Installer.

Timing Chain Assembly And Camshaft Sprocket:

Crankshaft Sprocket Removal:

Crankshaft Sprocket Installation:

REMOVE OR DISCONNECT
1. Engine front cover assembly.
2. Rotate crankshaft assembly until timing marks on crankshaft sprocket (24) and camshaft sprocket (92) are aligned to marks on engine block (52) or timing chain dampener (51). This is the number 1 piston at top dead center.
3. Camshaft sprocket bolt/screw (91).
4. Camshaft sprocket (92) and timing chain assembly (25).
5. Crankshaft sprocket (24) using J 23444-A.
6. Timing chain dampener bolts/screws (50) and dampener (51).

INSTALL OR CONNECT WITH TIMING MARKS
1. Crankshaft sprocket (24) using J 38612 until fully seated on flange of crankshaft nose.
2. Camshaft sprocket (92) and timing chain assembly (25).
3. Install chain damper to block.
4. Align crankshaft timing mark to timing mark on bottom of chain damper.
5. Hold car sprocket with the chain hanging down and install chain to crankshaft gear.
6. Align timing mark on camshaft gear (center line of locator hole) with timing mark on top of chain damper.
7. Camshaft sprocket bolt/screw (91).
Tighten bolts/screws (91) to 100 Nm (74 lb. ft.).

8. Timing chain dampener (51) and bolts/screws (50).
Tighten bolts/screws (50) to 25 Nm (18 lb. ft.).

9. Engine front cover assembly.


INSTALL OR CONNECT WITHOUT TIMING MARKS

This article has been updated with bulletin No.: 47-61-48.

REVISED TIMING CHAIN AND SPROCKET INSTALLATION PROCEDURE
^ If the camshaft gear does not have a timing mark, use the following procedure.

TOOLS REQUIRED: J 38612 Crankshaft Sprocket Installer.






INSTALL OR CONNECT
1. Crankshaft sprocket using J 38612.
2. Apply GM EOS P/N 1052367 or equivalent to the sprocket thrust surface.






3. Install timing chain dampener to cylinder block as shown.
4. Align the timing mark on the crankshaft sprocket to the timing mark on the bottom of the timing chain dampener.
5. Hold the camshaft sprocket with the timing chain hanging down and install the timing chain to the crankshaft gear.
6. Align the centerline of the locator hole, on the camshaft gear, with the timing mark on top of the timing chain dampener.
7. Align dowel in camshaft with dowel hole in camshaft sprocket.
8. Draw the camshaft sprocket onto camshaft using the mounting bolt.

Tighten Camshaft sprocket mounting bolt to 100 Nm (74 ft. lbs.).

9. Lubricate timing chain with engine oil.
10. Crankcase front cover.
11. Fill cooling system.
12. Negative battery cable.