GM 12564274
Timing Chain

However, to replace the Timing Chain, and sprocket, remove the engine front cover. Bring the timing marks on the sprockets as close together as it's possible, remove the Timing Chain dampener's bolt and bolt and unbolt the Timing Chain dampener. Next, the camshaft sprocket bolt, then camshaft sprocket and timing.concurrent retval; if the sprocket will not pose, it may be pried off with a light tap on the lower edge with a plastic mallet. When required, discard the crank shaft sprocket and the balance shaft drive gear to have easy access to camshaft thrust plate, including its bolts. Inspect all components for wear or damage. If the pistons have been moved, then rotate the Crankshaft to bring the number one Piston to the top dead center, and align the camshaft so that the timing mark is rendered straight down at that point with the sprocket temporarily fit. A balance shaft driven gear may be required to install, in such a case prevent the balance shaft from rotating when tight balance shaft driven gear bolt to 22 n.m (16 lb ft) plus an additional 70 degrees using the torque angle meter (J 45059). The camshaft thrust plate and bolts must be installed, which should be tightened to the value of 15 n.m (11 lb ft) and followed by the balance drive gear of the shaft. On balance shaft drive gear and balance shaft driven gear, put balance shaft timing marks in line, after that to install the Crankshaft sprocket and the Timing Chain and sprocket and put the timing marks in the line as close as possible. Install camshaft sprocket bolt, and tighten to 100 n.m (74 lb ft) and additional 90 degrees with the torque angle meter (J 45059), and then install the Timing Chain dampener and tighten its bolt to 22 n.m (16 lb ft). Finally turn the engine two revolutions to ensure that the timing marks are set before reinstalling the engine front cover.

The left Timing Chain replacement process begins by removing the right Timing Chain followed by removal of the left Timing Chain Tensioner and left camshaft cover. Make sure the drive pins of both camshaft sprockets position themselves at their highest rotational point. Install the camshaft holding tool (J 44212) on the camshafts to stop rotation when removing the left intake camshaft sprocket bolt. Use an open end wrench on the hex cast into the camshaft. First remove the left intake camshaft sprocket bolt before sliding the left intake camshaft sprocket from the camshaft position then disconnect the left Timing Chain from the camshaft sprocket teeth. Free the left Timing Chain from its position on the camshaft intermediate drive shaft sprocket teeth before extracting it out of the engine. During installation use the left cylinder head to feed down the left Timing Chain until it reaches the left exhaust camshaft sprocket and then direct the chain across the inner row of camshaft intermediate drive shaft sprocket teeth. The left intake camshaft sprocket should be installed through the left Timing Chain until it positions on the camshaft where the sprocket notch li creates contact with the intake camshaft pin. Use the open end wrench to stop rotation before torqueing the camshaft sprocket bolt to 120 nm (89 ft. Lbs.). Once the camshaft holding tool (J 44212) is removed you should install the left camshaft cover followed by the left Timing Chain Tensioner and complete the installation with the right Timing Chain.

The replacement of the Timing Chain starts with removing the Oil Pump. You need to align the timing marks through use of the crankshaft rotation socket (J 39946). Start with secondary camshaft drive chain removal followed by the Timing Chain tensioner alongside its retaining bolt for the camshaft intermediate sprocket. The technician should extract the Timing Chain combined with the crankshaft sprocket and the camshaft intermediate sprocket from the system as one unit. Place the timing marks of both the crankshaft sprocket and the camshaft intermediate directly vertical to each other during installation. First install the Timing Chain onto the drive sprockets when the number 1 piston sits at top dead center (TDC) position and the crankshaft keyway points towards the 1 o'clock direction. The crankshaft rotation socket (J 39946) allows you to properly position the crankshaft key on the drive sprocket. You should mount the camshaft intermediate sprocket with its retainer bolt together with the crankshaft sprocket and Timing Chain. Apply a torque of 60 nm (44 ft. Lbs.) to the bolt. Departure of the tensioner pin needs to wait until you install the secondary timing chains. Before that, install the Timing Chain tensioner then install the secondary camshaft drive chains. Release the tension on the Timing Chain through the lever by removing the pin and make sure the timing marks line up vertically before Oil Pump installation.

First, to replace the timing chain and sprockets, remove the Oil Pump. The crankshaft rotation socket (J 39946) should be used to align the timing marks. Then, get rid of the secondary timing chains and the primary drive chain tensioner. Subsequently, remove the camshaft intermediate sprocket retaining bolt and remove the crankshaft sprocket, camshaft intermediate sprocket as an assembly, and timing chain. Wash away the grime from the camshaft timing drive components before installation. Set the timing marks of camshaft intermediate and crankshaft sprockets vertically, installed. Mount the main timing chain on the drive sprockets; the number 1 piston should be in the raised position, while the crankshaft keyway is using the most preferred position at 1 o'clock. Mount the crankshaft rotation socket (J 39946) to align the crankshaft key with the drive sprocket, then fit the primary, drive, camshaft trust sprocket and under drive sprocket to camshaft intermediate as a fitting. Install the camshaft intermediate sprocket retaining bolt and tighten to 60 nm (44 ft. Lbs.). Make sure you do not take out the pin which holds the tensioner while the secondary timing chains are being installed. Mount the primary timing chain and subsequently the secondary timing chains. Dismount the pin from the primary timing chain tensioner release lever, make sure the primary timing marks are lined up vertically, and lastly, place the Oil Pump.

Remove the crankshaft sprocket and, if required, the balance shaft drive gear to access the camshaft thrust plate.

Again, using the EN-47719 (Tensioner Compressor), fully collapse the tensioner and place the retaining pin into the retaining hole.

Use the EN-47719 (Tensioner Compressor) to collapse the tensioner.

Remove the camshaft sprocket bolt, followed by the camshaft sprocket and the timing chain.

Slide the right exhaust camshaft position actuator off and remove the secondary timing chain from the actuator teeth.

Use an open wrench on the hex cast near the front of each camshaft for alignment.

Remove the right secondary camshaft drive chain tensioner, the camshaft position sensor, and the right camshaft cover.

Lift the chain from the camshaft intermediate drive shaft sprocket teeth and remove it from the engine.

Remove the J 44212 Camshaft Holding Tool.

Remove the primary camshaft drive chain, crankshaft sprocket, and camshaft intermediate sprocket.

Remove the camshaft covers and the camshaft position sensor.

Install the right secondary camshaft drive chain tensioner, remove the J 44212 from the camshafts, and then reinstall the right camshaft cover and CMP sensor.

Slide it down through the right cylinder head onto the right intake camshaft sprocket, routing it around the outer row of the camshaft intermediate drive shaft sprocket teeth.

Remove the camshaft covers and the camshaft position sensor.

Remove the pin from the release lever while ensuring the timing marks remain aligned vertically.

An open end wrench on the hex cast into the camshaft.

Ensure both camshaft sprocket drive pins are at the top of their rotation.

Slide it down through the right cylinder head onto the right intake camshaft sprocket, routing it around the outer row of the camshaft intermediate drive shaft sprocket teeth.

Clean and inspect all camshaft timing drive components, replacing any necessary parts.

Align the timing marks of the camshaft intermediate and crankshaft sprockets vertically.

Ensure both camshaft sprocket drive pins are at the top of their rotation.

Install the left camshaft cover, followed by the left secondary drive chain tensioner, and finally, install the right secondary camshaft drive chain.

Slide them off the camshaft and remove the secondary timing chain from the actuator teeth.

Use the open end wrench again to prevent rotation while tightening it to 120 Nm (89 ft. lbs.).

Install the left bank secondary camshaft drive chain guide.

Remove the engine front cover bolt.

Remove the left bank secondary camshaft drive chain tensioner.

Install the Camshaft Holding Tool (EN 46328) on the Bank 2 (left) camshafts.

First, remove the oil pump.

Take out the right bank secondary camshaft drive chain tensioner (Tensioner).

Lift the right secondary drive chain from the sprocket teeth and slide the camshaft sprockets off, letting the right chain fall into the front cover area, then remove it from the engine block.

The right bank secondary camshaft drive chain tensioner, chain shoe, and chain guide.

Repeat the process for the exhaust actuator and oil control valve.

Remove the J 44212 from the camshafts.

Start with the left bank secondary camshaft drive chain.

The Camshaft Holding Tool (EN 46328) is used on the bank 2 (left) camshafts.

Align the three black links with the corresponding timing marks on the bank 2 exhaust actuator, bank 2 intake actuator, and intermediate sprocket.

Loosen and remove the left secondary timing chain tensioner bolts and tensioner.

Install the primary camshaft drive chain on the drive sprockets.

Remove the engine front cover.

Caution is advised when using the Camshaft Holding Tool (EN 46328) on the bank 2 (left) camshafts.

Clean and inspect all components, replacing any that are necessary.

Reinstall the engine front cover.

Repeat the same process as for the bank 2 exhaust camshaft position oil control valve and actuator.

Use the Crankshaft Rotation Socket (J 39946).