GM 24504668
Timing Chain

For changing the Timing Chain and sprockets, one first collects all required tools, namely for example torque angle meter ( J 36660-A). Begin by removing the engine front cover and then align the marks of the timing sprockets as close as you can. Then, pull out the Timing Chain dampener, the camshaft sprocket bolt, the camshaft sprocket, and the Timing Chain sequentially. Before installing, clean and checked the Timing Chain and sprockets. Turn the Crankshaft to bring the number one piston to the top dead center and set the camshaft so that the timing mark is directly straight up with the Crankshaft sprocket temporarily attached. Install Timing Chain on the sprockets, ensure that the timing marks are very close to each other, replace with the latest install the Timing Chain, and then the sprocket on the Crankshaft, followed by the camshaft sprocket. Screw on the camshaft sprocket bolt and fasten it to 100 nm (74 ft lbs.) using the torque angle meter (J 36660-A) to turn the bolt a further 90 degrees. In consonance, fit the Timing Chain dampener including the bolt and tighten the Timing Chain dampener bolt to 22nm (16ft. Lbs.) and finish by reinstall the engine front cover.

Service and repair of the Timing Chain begins by obtaining the torque angle meter (J 36660-A) among other necessary tools. Start by taking off the engine front cover while you focus on setting the timing sprocket marks to align as near as possible. The service begins with Timing Chain dampener removal followed by camshaft sprocket bolt and camshaft sprocket extraction before Timing Chain retrieval. A thorough cleaning operation should precede sprocket and chain inspection for future installation. When the Crankshaft sits at top dead center position number one piston position make sure the camshaft timing mark points straight down as you temporarily secure the sprocket. Place the Timing Chain between the sprockets by lining up their timing marks. Install the Timing Chain followed by both the Crankshaft and camshaft sprockets. Apply 100 nm (74 ft. Lbs.) torque to the camshaft sprocket bolt followed by an additional 90° tightening sequence using the torque angle meter (J 36660-A). Set the Timing Chain dampener in place with its bolt followed by a 22 nm (16 ft. Lbs.) torque setting before reinstalling the engine front cover.

To replace the Timing Chain and the sprockets, start by removing the engine's front cover. Get as close as possible with the sprocket timing marks, right after the Timing Chain dampener and the bolt camshaft sprocket. If camshaft sprocket and Timing Chain comes off with difficulty, a gentle blow appertaining to the bottom side of the sprocket using a plastic mallet may be helpful to free it. Next, you have to disassemble the Crankshaft sprocket and if needed, the balance shaft drive gear to reach the camshaft thrust plate and its bolts. Check out all components for wear or damage then clean them. If the Piston has been moved either at the engine assembly plant or while the engine was installed, turn the Crankshaft, so, the number one Piston is at the top dead center and align the camshaft to have its timing mark facing straight down using the sprocket temporarily installed. For installing, if needed install balance shaft driven gear and lock concerning the balance shaft end so that it won't turn while install balance shaft driven gear bolt, torque it to 22 nm (16 ft. Lbs.) using electronic torque angle meter (J 36660-A) twist bolt 70 more degrees. Mount up the camshaft thrust plate with its bolts and tighten to 15 nm (11 ft. Lbs.), followed by the balance shaft drive gear. Ensure the timing marks are as close together as possible on the balance shaft drive gear and the balance shaft driven gear and align the timing marks, then install the Crankshaft sprocket/Timing Chain/sprocket. Replace the camshaft sprocket bolt, tightening the bolt to 100 nm (74 ft. Lbs) by using electronic torque angle meter (J 36660-A) to turn the bolt further 90 degrees. Lastly, fit the Timing Chain dampener and tighten the bolt to 22 nm (16 ft. Lbs), turn the engine two times to verify the alignment of the timing marks and fit the front cover of the engine.

To off the Timing Chain and sprockets, start with the removal of the engine front cover. While the timing marks on the sprockets are aligned as closely as possible, one should take out the Timing Chain dampener bolt and the Timing Chain dampener. Next remove the camshaft sprocket bolt and then even camshaft sprocket and timing oints were removed; if you find it difficult to get the sprocket off, a light tap at the lower edge with a plastic mallet can come in handy. Make sure you remove the crankshaft sprocket and also the balance shaft drive gear to access the camshaft thrust plate, remove the camshaft thrust plate bolts and the thrust plate if required. If necessary, also remove the balance shaft driven gear bolt, and the driven gear. Check and clean all timing parts for wear and tear. If the pistons have moved, you turn the crankshaft with the number one piston at the top dead center position and camshaft at the right angle with the timer mark straight down while the sprocket is temporarily installed. For installation, if necessary, install the balance shaft driven gear and lock out balance shaft while installing and tighten the driven gear angle bolt to 22 nm (16 ft. Lbs.) and then use the balancer shaft driven gear (J 36660-A) to bolt on 70 degrees. Mount the camshaft thrust plate and its bolts are should be tightened to 15 nm (11 ft. Lbs.), followed by balance shaft drive gear. Lining up the timing marks on the balance shaft drive gear and the driven gear, crankshaft sprocket, Timing Chain, camshaft sprocket to line them up as close as possible. Apply and tighten the camshaft sprocket bolt to 100 nm (74 ft lbs) than apply the torque angle meter (J 36660-A) and enlarge the bolt by 90 degrees. Lastly, put on the Timing Chain dampener and its bolt and tighten it to 22 nm (16 ft. Lbs.), turn the engine two times to match the timing marks and replace the engine front cover.

Use the Torque Angle Meter (J 36660-A) to tighten the camshaft sprocket bolt an additional 90 degrees.

Align the timing marks on the balance shaft drive gear and the balance shaft driven gear.

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

Remove the right bank secondary camshaft drive chain (Chain) and the primary camshaft drive chain tensioner (Tensioner).

Install the camshaft sprocket bolt and tighten it to 100 Nm (74 ft. lbs.) using the Torque Angle Meter (J 45059) to tighten the bolt an additional 90 degrees.

Remove the crankshaft sprocket and, if necessary, the balance shaft drive gear.

Turn the camshaft so that the timing mark is straight down with the sprocket temporarily installed.

Remove the spark plugs to facilitate crankshaft rotation.

Remove the spark plugs to facilitate crankshaft rotation.

Install the timing chain on the sprockets, aligning the timing marks, and then install the timing chain along with the crankshaft sprocket and camshaft sprocket.

Install the camshaft sprocket bolt and tighten it to 100 Nm (74 ft. lbs.) using the Torque Angle Meter (J 36660-A) to tighten the bolt an additional 90 degrees.

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

Install the primary upper camshaft drive chain guide (122).

Install the timing chain on the sprockets, aligning the timing marks.

Take off the engine front cover.

Install the camshaft sprocket bolt, tightening it to 100 Nm (74 ft. lbs.) and using the J 36660-A to rotate the bolt an additional 90 degrees.

Install the camshaft sprocket bolt and tighten it to 100 Nm (74 ft. lbs.).

Install the camshaft sprocket bolt and tighten it to 100 Nm (74 ft. lbs.), using the Torque Angle Meter (J 36660-A) to tighten the bolt an additional 90 degrees.

The timing chain, crankshaft sprocket, and camshaft sprocket.

Install the camshaft sprocket bolt and tighten it to 100 Nm (74 ft. lbs.), then use the Torque Angle Meter (J 36660-A) to tighten the bolt an additional 90°.

Use the Crankshaft Sprocket Installer (J 38612) to install the crankshaft sprocket, applying prelube GM P/N 1052365 or an equivalent to the crankshaft sprocket thrust surface.

Rotate the crankshaft until the camshaft alignment pin and the timing chain dampener are aligned with the crankshaft sprocket.

Place the timing chain on the sprockets, aligning the timing marks, and then install the timing chain along with the crankshaft sprocket and camshaft sprocket.

Place the timing chain onto the camshaft gear, hold the camshaft sprocket with the chain hanging down, and install the chain to the crankshaft gear.

Clean and inspect the timing chain and gears.

Align the timing marks on the balance shaft drive gear and the balance shaft driven gear, then install the crankshaft sprocket, timing chain, and sprocket, ensuring the timing marks are as close together as possible.

Begin by removing the engine front cover.

Install the timing chain on the sprockets, aligning the timing marks, and then install the timing chain along with the crankshaft sprocket and camshaft sprocket.