GM 24461834
Timing Chain, Green Line

The replacement process for Timing Chain sprockets and tensioner begins by disconnecting the car's negative Battery Cable then removing the camshaft cover followed by vehicle lift and support. Identify the second silver link at the 5 o'clock position by rotating the engine until the crankshaft sprocket mark reaches it. After lowering the vehicle check that the camshaft cover reveals the exh triangle on the exhaust camshaft sprocket at the 2 o'clock position matching the silver link. The int diamond on the intake camshaft sprocket must be at the 2 o'clock position matching the copper link. Start by removing the Timing Chain Tensioner alongside the Timing Chain Tensioner guide and Engine Mount and fixed Timing Chain Guide access plug and fixed Timing Chain Guide and upper Timing Chain Guide. Hold the camshafts still with a 24 mm wrench before discarding and removing the exhaust camshaft sprocket bolt and exhaust camshaft sprocket followed by removing the intake camshaft sprocket bolt and intake camshaft sprocket. The Timing Chain must be extracted first with access from the cylinder head's top followed by removal of the crankshaft sprocket and balance shaft drive chain tensioner and adjustable balance shaft chain guide and small balance shaft drive chain guide and upper balance shaft drive chain guide. All balance shaft drive chain slack will be obtained most easily when you remove the drive chain between crankshaft and water pump sprockets. After removing the balance shaft drive chain fit the upper balance shaft chain guide and tighten its bolts to 10 nm (89 inch lbs.). Install the adjustable balance shaft drive chain guide and its bolts at 10 nm (89 inch lbs.); next install the small balance shaft chain guide and tighten the balance shaft chain guide bolts to 10 nm (89 inch lbs.). Squeeze the tensioner plunger into position by turning it 90 degrees inside its bore until you can insert a paper clip through both holes in the plunger body. Then install the Timing Chain Tensioner followed by securing its bolts to 10 nm (89 inch lbs.). Lower the Timing Chain through the cylinder head opening by fitting the crankshaft sprocket at the 5 o'clock timing mark position so the chain circulates around both blocks (1,2). Install the intake camshaft timing sprocket at the 2 o'clock position with the int diamond visible then hand tighten a new intake camshaft sprocket bolt. Next position the Timing Chain around the crank shaft timing sprocket keeping the second silver link at the timing mark and the copper-colored link pointing to the int diamond on the intake camshaft. Feed the Timing Chain Tensioner guide through the cylinder head's upper opening then tighten the tensioner guide bolt to 10 nm (89 inch lbs.). Start by fixing the exhaust camshaft sprocket bolt through its Timing Chain silver link which must be positioned at the 10 o'clock exh triangle coordinated position. Use a 24 mm wrench to slightly turn the camshaft for exhaust sprocket alignment before hand tightening the new exhaust camshaft sprocket bolt. Trace the two fixed Timing Chain bolts to 10 nm (89 inch lbs.) before applying sealant from gm p/n 12345382 (Canadian P/N 10953489) compound onto threads and securing the Timing Chain cutout plug with a torque of 40 nm (30 ft. Lbs.). Put the Engine Mount in place while inspecting the Timing Chain Tensioner through replacement if it shows damage. The full length measurement of the Timing Chain Tensioner assembly should be taken. When installing a new tensioner it should measure 72 mm (2.83 inch) in its compressed non-active state when fully compressed. Install the j 45027-2 into a vise before inserting the notch-end of the Piston assembly. Then use the j 45027-1 to turn the ratchet cylinder into the Piston while it is held within the j 45027-2. Put the Piston assembly in the Timing Chain Tensioner body to reach the bottom of its bore without hitting against it. Before doing so check if dirt or damage exists in the tensioner body bore. Clean any discovered contamination. The tensioner should be 72 mm (2.83 inch) in total length during this measurement. Repeat the preceding steps if the length does not match. The cylinder head's Timing Chain Tensioner threaded hole must be free of all dirt before installing a new Timing Chain Tensioner assembly with a torque specification of 75 nm (55 ft. Lbs.). Using a suitable tool with a rubber tip apply compression force of 2 mm (0.079 inch) to the tensioner and use a 24 mm wrench to secure the camshaft while torquing new camshaft bolts to 85 nm (63 ft. Lbs.) plus 30 degrees. Completion of the engine repair requires camshaft cover installation followed by vehicle elevation to install the engine front cover then vehicle lowering to connect the negative Battery Cable. A suitable tool known as j 45027 tensioner tool (J 45027) serves as necessary equipment.

A correct repair of the Camshaft Timing Chain starts with removing the number 1 cylinder Spark Plug by rotating the Crankshaft clockwise until the compression stroke moves the number 1 Piston to top dead center (TDC). Begin by taking off both the Camshaft cover and the engine front cover. Disassemble the Timing Chain Guide bolts before guide removal then detach the tensioner to release chain tension. A 24 mm sized wrench should be used to maintain the exhaust Camshaft while discarding the exhaust Camshaft actuator bolt before extracting the actuator from the Camshaft and Timing Chain. The following items must be removed before proceeding: Timing Chain tensioner guide bolt and guide along with the fixed Timing Chain Guide access plug and fixed Timing Chain Guide bolts and guide. Perform these steps again for the intake Camshaft actuator by first taking out both Timing Chain elements and Crankshaft sprocket components. When changing the balance shaft Timing Chain replace the balance shaft drive chain tensioner bolts with tensioner before installing adjustable and small balance shaft drive chain guides. Set the balance shaft drive sprocket and chain into position while directing the colored links to match the sprocket timing marks. Install the upper and small balance shaft drive chain guides while tightening bolts to 15 nm (11 lb ft) and 10 nm (89 lb in) using torque wrenches. Bring the Timing Chain Tensioner plunger to its initial position before installing the tensioner while making sure the intake and exhaust Camshaft notches face their exact locations. Place the Timing Chain drive sprocket with its 5 o'clock timing mark visible before installing the special link on the intake Camshaft actuator. Then position the Timing Chain correctly around the Crankshaft sprocket. Verify that the colored link alignment matches the timing marks before tightening new actuator bolts. Mount the fixed and upper Timing Chain guides, torquing their bolts to 12 nm (106 lb in) and 10 nm (89 lb in). To install the tensioner assembly properly you must: reset the Timing Chain Tensioner first and check the seal for damage while cleaning the threaded hole before tightening the assembly to 75 nm (55 lb ft). The tensioner requires tool-assisted release after which the intake and exhaust Camshaft actuator bolts require tightening to 30 nm (22 lb ft) with additional turn of 100 degrees using j 45059. Finish the installation by inserting the Timing Chain oiling nozzle then cover the guide bolt access hole plug with gm p/n 12345382 sealant compound before tightening to 90 nm (66 lb ft). The service procedure includes reinstalling the engine front cover and Camshaft cover and number 1 cylinder Spark Plug.

For removal of Timing Chain, sprockets, or tensioner, collect the needed tools:. Tensioner tool (J 45027). Unbolt the Camshaft cover and lift the vehicle. Then take away engine front cover and bring the vehicle down. A 24-mm open-end wrench is used to rotate the Camshaft clockwise, putting the number 1 Piston around 60 degree to top dead center (TDC). Take off the spark plugs to facilitate rotation. Go ahead and take out the Timing Chain Tensioner, fixed Timing Chain Guide access plug, fixed Timing Chain Guide, upper Timing Chain Guide, and hold the camshafts using a 24 mm wrench. The part to be removed next is the exhaust Camshaft sprocket bolt which is to be removed and discarded. Next is removal of the exhaust Camshaft sprocket, Timing Chain tensioner guide, intake Camshaft sprocket bolt and finally the intake Camshaft sprocket. Eliminate the Timing Chain from the top of the cylinder head as well as two crankshaft sprocket, oil nozzle and bolt, balance shaft drive chain tensioner, adjustable balance shaft chain guide, small balance shaft drive chain guide, upper balance shaft drive chain guide. If removal of the balance shaft drive chain proves troublesome, the air intake pipes need to have all slack taken up between the crankshaft and water pump sprockets. For installation, begin with the upper chain guide for the balance shaft much like you tighten up the bolts on it to 10 nm (89 inch lbs.). Scribble cam balance shaft drive chain, aligning the colored links with timing marks on the sprockets. Install the small balance shaft chain guide and tighten bolts to 10 nm (89 inch lbs) followed by adjustable balance shaft drive chain guide of the same torque value. Turn the tensioner plunger by 90 degrees, press it until the paper clip can be inserted, and then install Timing Chain Tensioner and tighten its bolts to 10 nm (89 inch lbs). Consequently, take off the paper clip, put the oil nozzle and bolt, tighten to 10 nm (89 inch lbs.), and install the crankshaft sprocket with the timing mark at the 5 o'clock position. Lower Timing Chain through the cylinder head taking along the opension around both sides of the cylinder block bosses. Install the intake Camshaft sprocket and set theint diamond at 2:00 position; hand-tight a new intake Camshaft sprocket bolt. Run the Timing Chain around the crankshaft and intake Camshaft sprockets so that the links with the corresponding colors are matched. After that, install the Timing Chain Tensioner guide and tighten its bolt at 10 nm (89 inch lbs); install the exhaust Camshaft sprocket with the same colored link at the triangle of exh at the 10 o'clock position. Shift the Camshaft slightly with a 24 mm wrench till the exhaust sprocket comes into line, then bolt a new exhaust Camshaft sprocket with a wrench by hand. Mount the fixed Timing Chain Guide and tighten the bolt to 10 nm (89-inch lbs), apply sealant on the Timing Chain Guide bolt access hole plug, and tighten to 90 nm (59 ft. Lbs). Mount the Timing Chain upper guide and lock up its bolts to 10 nm (89 inch lbs.). Check the tensioner Timing Chain and, if needed, replace it. Measure the tensioner assembly Timing Chain. Round up to two decimals: it should be 72mm (2.83 inch) when fully compressed. Otherwise, pull out the Piston assembly, place it in j 45027-2 in a vise, and insert a Piston assembly then apply torque to the ratchet cylinder using j 45027-1. Clean the tensioner bore and then install the compressed Piston assembly with the assembly measuring about 72mm (2.83 inch). Put on the Timing Chain Tensioner and tighten to 75 nm (55 ft. Lbs.). Use adequate tools with rubber tip to release the tensioner, while using a 24mm wrench to hold the cam shaft, the following is done; tight the replacing cam shaft together with the bolts in 85 nm (63 ft. Lbs) along with the 30°. Finally, tighten the Camshaft cover, lift the vehicle, install the engine front cover, drop the vehicle and connect the negative Battery Cable.

Before doing these jobs, you will have to remove the engine front cover first. Turn on the Crankshaft until there is a match in terms of the timing marks. The camshaft alignment pin and the Timing Chain dampener to the Crankshaft sprocket. Then, unbolt the camshaft sprocket, then remove the camshaft sprocket with the Timing Chain, followed again by the Crankshaft sprocket. Take out the Timing Chain dampener bolts and Timing Chain dampener. If required, you should withdraw the camshaft thrust plate bolts and as well as the thrust plate. Furthermore, examine the Timing Chain and gears and give them a thorough cleaning. For installation if camshaft thrust plate was removed, install it in such a way as to tighten the thrust plate bolts to 10 nm (89 inch lbs.). It is advisable to install the Crankshaft sprocket and applying engine oil supplement (EOS) gm p/n 1052367 (Canadian P/N 992869) to the sprocket thrust surface. Install the Timing Chain dampener and tighten the dampener bolts to 21 nm (15 ft. Lbs.). Position the Timing Chain around the cam shaft gear, hold the cam shaft sprocket with the chain dangling, and then connect the chain to the crank shaft gear. Match up the crank shaft timing mark with the timing mark on the bottom of the Timing Chain dampener, and match up the timing mark on the cam shaft gear center line of the locator hole with timing mark on the top of the chain dampener. Make sure the dowel in the camshaft fits into the dowel hole in the sprocket for the camshaft. Mount the camshaft sprocket to the camshaft using the mounting bolt and secure it with 140 nm (103 ft. Lbs.). Draw camshaft sproket onto camshaft and tighten with 140 nm (103 ft. Lbs). Finally, oil the Crankshaft and the camshaft sprocket and replace the front cover of the engine.

Remove the right bank secondary camshaft drive chain tensioner (Tensioner), the right bank secondary camshaft drive chain shoe (Shoe), and the right bank secondary camshaft drive chain guide (Guide).

Ensure the timing mark is correctly positioned before installation.

Remove the piston assembly, use J 45027-2 in a vise, install the piston assembly, and turn the ratchet cylinder with J 45027-1.

Remove the timing chain tensioner guide, engine mount, fixed timing chain guide access plug, fixed timing chain guide, intake camshaft sprocket bolt, and intake camshaft sprocket.

Install the timing chain oiling nozzle, apply sealant to the timing chain guide bolt access hole plug, and install it, followed by the engine front cover, camshaft cover, and the number 1 cylinder spark plug.

Clean the tensioner bore, install the compressed piston assembly, and ensure it measures approximately 72 mm (2.83 in) from end to end.

Remove the engine front cover and align the crankshaft sprocket and camshaft sprocket timing marks with the alignment tabs on the timing chain tensioner.

Remove the camshaft cover and raise the vehicle.

Take off the exhaust and intake camshaft sprockets, timing chain, crankshaft sprocket, oil nozzle and bolt, balance shaft drive chain tensioner, adjustable balance shaft chain guide, small balance shaft drive chain guide, and upper balance shaft drive chain guide.

Rotate the crankshaft clockwise to remove slack, then install the adjustable timing chain guide and bolt.

Remove the balance shaft drive chain tensioner bolts and tensioner, followed by the adjustable and small balance shaft drive chain guides, then remove the balance shaft drive chain and sprocket.

Turn the tensioner plunger 90 degrees, compress it until a paper clip can be inserted, then install the timing chain tensioner and tighten its bolts to 10 Nm (89 lb in).

Rotate the camshaft slightly with a 24 mm wrench until the exhaust sprocket aligns, then hand tighten a new exhaust camshaft sprocket bolt.

Remove and discard the exhaust camshaft sprocket bolt.

Rotate the plunger and insert a paper clip, then install the balance shaft drive chain tensioner and bolts, tightening to 10 Nm (89 lb in).