GM 12575882
Camshaft Gear

To replace the primary timing chain and sprockets, initial, remove the Oil Pump. Instead, align the primary timing marks with the help of the crankshaft socket (J 39946). Then, take off the drive chains for the secondary camshaft and the primary timing chain tensioner. First, remove the camshaft intermediate retaining bolt and pull out the primary timing chain, crankshaft sprocket, and the camshaft intermediate sprocket as a single unit. Check out camshaft timing drive components, clean, and inspect. For the installation, position the timing mark of the camshaft intermediate and crankshaft sprockets vertically and fit the primary timing chain on the drive sprockets. Make sure to take the number 1 piston to top dead centre (TDC) with the crankshaft keyway at 1 o'clock, with the help of the tool crankshaft socket (J 39946), align the crankshaft key to the drive sprocket. Put in the main timing chain, the crankshaft sprocket, and the camshaft mid-sized sprocket together, and tighten the camshaft mid-sized sprocket retaining bolt to 60 n.m (44 lb ft). Do not take off the pin securing the tensioner until the second timing chains are in place. Mount the primary timing chain tensioner and then secondly the secondary camshaft drive chains. Lastly, pull out the pin from the primary timing chain tensioner release lever and align the primary timing marks vertically before fitting back the Oil Pump.

Use the Crankshaft Socket (J 39946).

Install the primary camshaft drive chain, crankshaft sprocket, and camshaft intermediate sprocket as an assembly.

Remove the pin from the primary timing chain tensioner release lever and ensure the primary timing marks are aligned vertically.

Begin by removing the oil pump.

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