Timing Chain & Sprockets (Camshaft): Installation

1. Align crankshaft keyway with timing mark on block. Ensure arrow on idler sprocket is at 6 o'clock position, and guide pins on camshaft sprockets are aligned with notches on cylinder head. See Figure. Align Yellow link on camshaft timing chain with arrow on idler sprocket. See Fig 1.
   CAUTION: Ensure all timing marks are aligned after timing chain is installed.
2. Align Dark Blue links on camshaft timing chain with arrows on camshaft sprockets. See Fig 2. Install camshaft sprockets and chain. Install camshaft sprocket bolts and tighten to specification. See TORQUE SPECIFICATIONS .
3. Depress camshaft timing chain tensioner plunger into tensioner body. Insert paper clip or similar retainer through hole in tensioner body to keep plunger in place. See Figure. Install timing chain tensioner bolts and nut. Tighten to specification. See TORQUE SPECIFICATIONS . Remove plunger retainer.
4. Turn crankshaft 2 revolutions and realign keyway on crankshaft with timing mark on engine. Ensure guidepins on camshafts line up with notches on cylinder head. Apply engine oil to sprockets, timing chain, timing chain tensioner, and guides.
5. To complete installation, reverse removal procedure. Tighten bolts to specification. See TORQUE SPECIFICATIONS . On 4WD models, adjust front wheel toe-in. See appropriate SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT.

Fig 1: Aligning Camshaft Timing Chain & Idler Sprocket

Courtesy of GENERAL MOTORS CORP.

Fig 2: Aligning Camshaft Timing Chain & Camshaft Sprockets

Courtesy of GENERAL MOTORS CORP.