Removal Procedure

WARNING: This page is about a different car, the 2003 GMC Sonoma and 2003 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.

Remove the engine front cover. Refer to ENGINE FRONT COVER REPLACEMENT .
NOTE: In order to rotate the engine install a bolt with the same threads as the crankshaft, but do not use the crankshaft balancer bolt or a bolt longer than 1 inch, in the crankshaft. Failing to do so will cause damage to the bolt threads and the crankshaft threaded hole when removing the bolt.
Install a bolt in the end of the crankshaft.
NOTE: Align the timing marks before removing the timing chain. If it is necessary to turn either the camshaft or the crankshaft with the timing chain removed, loosen or remove the valve rocker arms. Turning either the crankshaft or camshaft with the timing chain removed may cause the pistons to contact the valves, resulting in damage.

Fig 1: Aligning Timing Marks
Courtesy of GENERAL MOTORS CORP.
Rotate the crankshaft until the number 1 piston is at Top Dead Center (TDC) of the compression stroke.
Make sure the camshaft sprocket alignment mark, which is an 8 mm (0.31 in) hole, and the stamped circle in the crankshaft sprocket align with the tabs on the timing chain tensioner.

Important: Before removing the timing chain, measure the distance between the hole in the bracket and the unworn surface of the timing chain tensioner shoe.

If the distance between the hole and the unworn surface of the timing chain tensioner shoe is more than 8 mm (0.314 in), replace the tensioner, timing chain, and both sprockets.
Remove the timing chain tensioner bolts.

Fig 2: Removing Timing Chain Tensioner Bolts
Courtesy of GENERAL MOTORS CORP.

NOTE: Do not replace only the tensioner or the chain to correct a noise condition caused by the camshaft drive components. When replacing the tensioner or chain to correct a noise condition all of the camshaft drive components must be replaced.
Remove the timing chain, the timing chain tensioner, and the camshaft sprocket at the same time.
If replacing camshaft, remove the camshaft position sensor. Refer to CAMSHAFT POSITION SENSOR in Removal & Installation in Engine Performance.

Fig 3: Removing Timing Chain, Timing Chain Tensioner, And Camshaft Sprocket
Courtesy of GENERAL MOTORS CORP.
Remove the crankshaft sprocket. Use the J 22888-20A .
Clean and inspect the timing chain and sprockets.

Fig 4: Removing Crankshaft Sprocket
Courtesy of GENERAL MOTORS CORP.