Removal Procedure

Remove the camshaft cover. Refer to Camshaft Cover Replacement (LTG) .
NOTE: Ensure the engine is properly timed to Top Dead Center (TDC), prior to performing repairs.
Remove the high pressure fuel pump. Refer to Fuel Pump Replacement .
Install EN-50656 timing chain holding tool (1) and tighten to 8 N.m (71 lb in).

Fig 1: Identifying Timing Chain Holding Tool
Courtesy of GENERAL MOTORS COMPANY

NOTE: Ensure the EN-50656 holding tool is installed and securely tightened to prevent the camshaft chain from dropping into the front engine cover during camshaft actuator replacement.
Align and install camshaft actuator locking tool (2) EN 50793 into the slots of the exhaust camshaft actuator and mount tool to engine front cover assembly and tighten the bolts (1) to 10 N.m (89 lb in).

Fig 2: Camshaft Actuator Locking Tool
Courtesy of GENERAL MOTORS COMPANY

CAUTION: Refer to Fastener Caution .

NOTE: Ensure to mark actuator sprocket and chain before removal.
Remove and DISCARD the camshaft actuator bolt (1).

Fig 3: Camshaft Actuator Bolt
Courtesy of GENERAL MOTORS COMPANY
Remove the EN-50793 holding tool (2).

Fig 4: Camshaft Actuator Locking Tool
Courtesy of GENERAL MOTORS COMPANY
Remove the upper timing chain guide bolts (1, 2).

Fig 5: Upper Timing Chain Guide Bolts
Courtesy of GENERAL MOTORS COMPANY
Remove the upper timing chain guide (3).
Remove the camshaft front bearing cap bolts (4).
Remove the camshaft front bearing cap (5).
NOTE: Locate the pry points (6) in the camshaft front bearing cap. When using the 3 pry points to remove the front bearing cap evenly, use a protective material between the camshaft lobes, the cylinder head flange and pry tool.
Mark the exhaust camshaft rear cap to ensure it is installed in the same position. Remove the exhaust camshaft bearing rear cap bolts (1) and cap (2).

Fig 6: Exhaust Camshaft Bearing Rear Cap Bolts And Cap
Courtesy of GENERAL MOTORS COMPANY
Mark the camshaft caps (4) to ensure they are installed in the same position.
NOTE: Loosen each bolt on each cap one turn at a time until there is no spring tension pushing on the camshaft.
Remove the exhaust camshaft cap bolts (3).
Remove the camshaft caps (4).
Pull exhaust camshaft actuator assembly forward away from camshaft assembly (1), then lift rear of exhaust camshaft assembly to a tilt and pull free from exhaust camshaft actuator assembly (2).

Fig 7: Camshaft Assembly
Courtesy of GENERAL MOTORS COMPANY
Mark the intake camshaft rear cap to ensure it is installed in the same position. Remove the intake camshaft bearing rear cap bolts (1) and cap (2).

Fig 8: Intake Camshaft Bearing Rear Cap Bolts And Cap
Courtesy of GENERAL MOTORS COMPANY
Mark the camshaft caps (4) to ensure they are installed in the same position.
NOTE: Loosen each bolt on each cap one turn at a time until there is no spring tension pushing on the camshaft.
Remove the intake camshaft cap bolts (3).
Remove the camshaft caps (4).
Lift and roll intake camshaft assembly from original position over into exhaust camshaft position within engine head assembly.
Align and install camshaft actuator locking tool (2) EN 50793 into the slots of the intake camshaft actuator and mount tool to engine front cover assembly and tighten the bolts (1) to 10 N.m (89 lb in).

Fig 9: Camshaft Actuator Locking Tool
Courtesy of GENERAL MOTORS COMPANY
Remove the camshaft actuator bolt (1).

Fig 10: Camshaft Actuator Bolt
Courtesy of GENERAL MOTORS COMPANY
Remove the EN-50793 holding tool (2).

Fig 11: Camshaft Actuator Locking Tool
Courtesy of GENERAL MOTORS COMPANY
Pull intake camshaft actuator assembly forward away from camshaft assembly (1), then lift rear of intake camshaft assembly to a tilt and pull free from intake camshaft actuator assembly (2).

Fig 12: Camshaft Assembly
Courtesy of GENERAL MOTORS COMPANY
Replace the camshaft if necessary.
NOTE: If replacing the camshaft, ensure to transfer any marking from the old camshaft to the new one.