GM 12578515
Camshaft Gear, Green Line

Start the replacement procedure of the Camshaft position intake actuator by first removing the Camshaft cover and then the spark plugs. Afterward remove both upper Timing Chain Guide bolts and the guide itself. Before final installation of the Camshaft actuator retainer (EN-48953) you must rotate the Crankshaft clockwise while securing retainer bolts at 10 nm (89 lb in) torque value. You should loosen the intake Camshaft actuator bolt but keep it attached while you remove the Camshaft actuator locking tool (EN-48953). Mark down the positions of the intake and exhaust Camshaft actuators and proceed to take out bolts from the upper timing guide, guide and tensioner system. Check for any movement of the Camshaft actuators as well as confirm full rod insertion at the Timing Chain during this time. The mechanical retention tool en-48749 should be installed to both Timing Chain sides prior to removing and discarding the intake Camshaft actuator bolt. You must turn the exhaust Camshaft a small amount clockwise to reduce chain tension before taking out the intake Camshaft actuator from the Camshaft position. Install the Timing Chain on the intake Camshaft actuator following the reference alignment points before fitting the actuator to the Camshaft through clockwise rotation of the exhaust Camshaft if required. If the new intake Camshaft actuator bolt reaches proper torque levels, users should remove both chain retention tools. Commence the procedure by installing the Timing Chain Tensioner before moving onto installing the Camshaft actuator retainer. Strengthen the retainer bolts to 10 nm (89 lb in) and the new Camshaft actuator bolt needs 30 nm (22 lb ft) and a 100 degree addition checked with an angle meter (J 45059). Crank the Crankshaft balancer to the opposite direction until the tensioner releases and subsequently torque the bolt to 45 nm (33 lb ft). The final step includes removing the Camshaft actuator retainer (EN-48953), installing the upper Timing Chain Guide followed by bolting it in place to 10 nm (89 lb in). Proceed with reinstalling spark plugs and the Camshaft cover.

Replace the camshaft position exhaust actuator by firstly stripping away the camshaft cover along with all spark plugs. Mount the Crankshaft with clockwise rotation before you put the camshaft actuator retainer (EN-48953) into position. Fasten the camshaft actuator retainer bolts with a torque of 10 nm (89 lb in). The exhaust camshaft actuator bolt should remain untouched while cleaning the Timing Chain and gears with solvent along with marking both the Timing Chain and camshaft position actuators for correct reassembly. Before upper Timing Chain guide removal the technician should mark the intake and exhaust camshaft actuators with their corresponding positions on the Timing Chain. The retention tool (EN-48749) needs to be inserted in the Timing Chain before removing or installing the camshaft actuators while preventing actuator rotation. Use tool en-48749 to install the retention mechanism on the exhaust side of the Timing Chain before taking out and discarding the exhaust camshaft actuator bolt then remove the exhaust camshaft actuator from the camshaft and the Timing Chain. To install the Timing Chain properly place it on the exhaust camshaft actuator before aligning the identifier mark of both elements. Then tighten a new exhaust camshaft actuator bolt until it becomes snug. Check the alignment mark on the exhaust camshaft actuator for correctness since possible adjustments might be required. The Timing Chain retention device must be removed from the exhaust side while also resetting and installing the Timing Chain Tensioner before putting on the stock intake camshaft actuator retainer along with bolting it to a torque of 10 nm (89 lb in). Finish tightening the new camshaft actuator bolt to 30 nm (22 lb ft) with a high torque value of 100 degrees that should be read using an angle meter (J 45059). You must discharge tension from the retainer by giving the Crankshaft balancer bolt a 45 nm (33 lb ft) counterclockwise torque before taking out the camshaft actuator retainer (EN-48953). Add the upper Timing Chain guide with bolts which require 10 nm (89 lb in) torque before fixing the camshaft cover along with spark plugs.

Before installing the Camshaft position intake actuator the mechanic must remove the Camshaft cover along with upper Timing Chain Guide bolts and guide. A 24 mm wrench (J 44217) should be used to secure the Camshaft during bolt loosening yet the intake Camshaft actuator bolt remains intact. The Timing Chain tensioner tool (J 44217) should have its tips extended completely into the Timing Chain for replacement purposes. The Timing Chain tensioner tool (J 44217) has one tool that must be installed on the exhaust Camshaft side to hold the Timing Chain before tightening its nuts firmly. Use another tool from the Timing Chain tensioner tool (J 44217) to perform the same operation on the intake Camshaft side. Tag the positioning and location markings for intake and exhaust Camshaft actuators which are present on the Timing Chain. Extract the intake Camshaft actuator bolt and discard it afterward while removing the intake Camshaft actuator from its position on the Camshaft and Timing Chain. When installing the exhaust Camshaft actuator make sure its alignment mark matches the Timing Chain mark precisely. The Timing Chain should be fitted on the intake Camshaft actuator with proper alignment to the Timing Chain mark before installing the actuator onto the Camshaft unit. Fasten the new intake Camshaft actuator bolt until secure but continue holding the tools in place on both the intake and exhaust Camshaft Timing Chain assembly sides before removing them. After securing the Camshaft using a 24 mm wrench (J 44217) you must tightly tighten the new Camshaft actuator bolt to 85 n.m (63 lb ft) by adding another 30 degrees using the angle meter (J 45059). Install the upper Timing Chain Guide followed by its bolts while torquing them to 10 n.m (89 lb in) then replace the Camshaft cover.

Hold the camshaft with the 24 mm wrench (J 44217) and tighten the new camshaft actuator bolt to 85 Nm (63 ft. lbs.), plus an additional 30 degrees using the Angle Meter (J 45059).

Place the timing chain onto the exhaust camshaft actuator, align the actuator with the timing chain mark.

Install the EN-48953 (Camshaft Actuator Locking Tool) retention tool.

Install the camshaft actuator retainer (EN-48953) and tighten the bolts to 10 Nm (89 lb in).

Install the timing chain onto the exhaust camshaft actuator, aligning the actuator with the timing chain mark.

Tighten it to 75 N.m (66 lb ft).

Remove the upper timing chain guide bolts and guide, followed by the timing chain tensioner.

Use a 24 mm wrench to hold the camshaft while loosening, but not removing, the intake camshaft actuator bolt.

The upper timing chain guide bolts and guide, followed by the timing chain tensioner.