GM 12586533
Intake Camshaft

The first step for Camshaft replacement involves removing both the Camshaft cover as well as the intake and exhaust Camshaft sprocket bolts. You should use the Camshaft sprocket holding tool (J 44222) to attach it to the Cylinder Head before adjusting the horizontal bolts into the Camshaft sprockets which both maintain chain tension and prevent disturbances of Timing Chain components. Before removing the Camshaft bolts separate the sprockets with Timing Chain from the camshafts by using a rack to store the Camshaft caps for correct installation. Start by placing the Camshaft caps into storage and afterward detach the camshafts from the engine compartment. Engine oil must be applied to the Camshaft journal surface and its thrust area before positioning the camshafts into their original locations. Clean engine oil should also be used to coat the Camshaft lobes and journals. Use the Camshaft holding tool (J 44221) with its flats facing upwards at cylinder number 1 while the piston is at top dead center position. Use the original positions for the Camshaft caps because their direction and numerical sequence is clearly marked by pin stamping and torque the bolts to 12 nm (106 inch lbs.). First remove both Camshaft holding tools (J 44221 and J 44222). Then place the sprockets securely back onto the camshafts before removing the tools. Drive the intake Camshaft sprocket bolt to 20 nm torque and finish tightening it to an extra 100 degrees using the torque/angle meter (J 36660-A). Tighten the exhaust Camshaft actuator bolt to 25 nm initially before ending at 135 degrees with the torque/angle meter (J 36660-A). Use the torque/angle meter (J 36660-A) to perform two passes on the exhaust Camshaft actuator bolt where the first application provides 25 nm (18 ft. Lbs.) torque then the second maneuver adds 135 degrees rotation. Finally, install the Camshaft cover.

Begin by taking out the Camshaft cover as well as the bolts from the intake and exhaust Camshaft sprockets. The technician should install the Camshaft sprocket holding tool (J 44222) on the Cylinder Head with horizontal bolts that keep the chain taut while preserving the Timing Chain structure. Maintain proper placement of Camshaft caps on a rack before you start removing the Camshaft cap bolts. First remove both Camshaft caps with the camshafts from their locations. Clean engine oil treatment precedes Camshaft intake and exhaust installation onto their original alignment positions. Secure the Camshaft holding tool (J 44221) with Camshaft flats facing up when placing the number 1 cylinder at top dead center. Use the original Camshaft cap mounting locations since they display numerical order and direction pin stamping for correct installation before tightening the Camshaft cap bolts to 12 n.m (106 lb in). Remove the Camshaft holding tool (J 44221) before placing the sprockets onto the camshafts and taking out the Camshaft sprocket holding tool (J 44222). Tighten the intake Camshaft sprocket bolt to 20 n.m (15 lb ft) on the initial pass and finish the bolt torque by rotating it through an additional 100 degrees using the torque/angle meter (J 36660-A). The procedure to tighten the exhaust Camshaft actuator bolt requires initial tightening to 25 n.m (18 lb ft) followed by additional tightening to a 135-degree torque with the torque/angle meter (J 36660-A). Finally, install the Camshaft cover.

Tighten them with bolts to 12 Nm (106 lb in).

Coat them with clean engine oil.

Remove the camshaft sprocket and reposition the timing chain, followed by the removal of the camshaft retainer bolts and retainer.