I have listed below the procedures for removal/installation of the timing chain for your 2.8L engine. Ensure that you did these steps and that you have the chain in time.
NOTE: The following procedure requires the use of the Crankshaft Sprocket Removal tool No. J-5825-A or equivalent, and the Crankshaft Sprocket Installation tool No. J-5590 or equivalent.
Remove the timing cover from the engine.
Rotate the crankshaft until the No. 4 cylinder is on the TDC of it's compression stroke and the camshaft sprocket mark aligns with the mark on the crankshaft sprocket (facing each other at a point closest together in their travel) and in line with the shaft centers.
Remove the camshaft sprocket-to-camshaft nut and/or bolts, then remove the camshaft sprocket (along with the timing chain). If the sprocket is difficult to remove, use a plastic mallet to bump the sprocket from the camshaft.
The camshaft sprocket (located by a dowel) is lightly pressed onto the camshaft and should come off easily. The chain comes off with the camshaft sprocket.
If necessary use J-5825-A or an equivalent crankshaft sprocket removal tool to free the timing sprocket from the crankshaft.
Using a putty knife, clean the gasket mounting surfaces. Using solvent, clean the oil and grease from the gasket mounting surfaces.
If removed, use J-5590, or an equivalent crankshaft sprocket installation tool and a hammer to drive the crankshaft sprocket onto the crankshaft, without disturbing the position of the engine.
During installation, coat the thrust surfaces lightly with Molykote or an equivalent pre-lube.
Position the timing chain over the camshaft sprocket. Arrange the camshaft sprocket in such a way that the timing marks will align between the shaft centers and the camshaft locating dowel will enter the dowel hole in the cam sprocket.
Position the chain under the crankshaft sprocket, then place the cam sprocket, with the chain still mounted over it, in position on the front of the camshaft. Install and tighten the camshaft sprocket-to-camshaft retainers to 17 ft. lbs. (23 Nm) for 2.8L engines or to 21 ft. lbs. (28 Nm) for 4.3L engines.
With the timing chain installed, turn the crankshaft two complete revolutions, then check to make certain that the timing marks are in correct alignment between the shaft centers.
Install the timing cover.
The marks should align with each other and the reference tabs on the timing chain tensioner
Sunday, November 23rd, 2008 AT 9:26 PM