REMOVAL & INSTALLATION
See Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 and 14
During this procedure, identify all components removed from the engine so that they may be reinstalled in their original positions. If discarding the old components so that new components can be installed, identifying the old items is not necessary.
- Remove the timing chain cover from the engine.
- Rotate the crankshaft clockwise until the crankshaft sprocket, idler sprocket, camshaft sprocket and engine timing marks are positioned as shown in the accompanying illustration.
Ensuring the crankshaft, idler sprocket and camshafts are correctly positioned is vital for timing chain installation.
- Remove the outer timing chain tension adjuster mounting bolts, then remove the adjuster from the cylinder head by rotating the intake camshaft counterclockwise a little while depressing the adjuster contact pad.
- Hold the intake camshaft steady by using an open end wrench on the hexagonal section of the camshaft, then loosen the camshaft sprocket retaining bolt. Loosen the exhaust camshaft sprocket retaining bolt in the same manner.
- Remove the camshaft sprockets from the ends of the camshafts, then lift the sprockets and chain up and off of the engine.
- Remove the inner timing chain guide by loosening the mounting fasteners and separating it from the engine block.
- Remove the inner timing chain tension adjuster and contact arm (tensioner) from the engine block.
- Remove the timing chain idler pulley from the cylinder head, drop the idler sprocket and inner timing chain down to disengage it from the crankshaft sprocket, then remove the inner timing chain and idler pulley from the engine.
- Slide the crankshaft timing chain sprocket off of the end of the crankshaft.
- Clean all components of all dirt and oil.
Inspect the following timing chain components for wear and/or damage. Replace any items found to be worn, defective or damaged:
Inner and outer timing chain guide contact surfaces
- Ensure that the latch and tooth surfaces of the inner timing chain tensioner are free from damage and that the latch functions properly.
- Ensure that the crankshaft timing sprocket key is aligned with the timing mark on the engine block. If the engine was assembled so that the crankshaft is not properly positioned, remove the hydraulic valve lash adjusters so that the crankshaft may be rotated to the proper position.
- Slide the crankshaft timing gear onto the end of the crankshaft so that the key in the crankshaft is aligned with the slot in the gear.
- Apply clean engine oil to the idler gear bushing, then drape the inner timing chain on the idler sprocket so that the dark blue chain piece is aligned with the matchmark on the idler sprocket. Position the timing chain around and under the crankshaft sprocket so that the yellow chain piece is aligned with the matchmark on the crankshaft sprocket. Install the idler sprocket and sprocket shaft in the cylinder head.
- Install the inner timing chain contact arm (tensioner), then tighten the pivot bolt to 19 ft. lbs. (25 Nm).
- With the latch of the inner timing chain tension adjuster returned and the plunger fully depressed into the adjuster, insert a pin into the latch and adjuster body. With the pin installed, the plunger should not come out of the adjuster body.
- Install the inner timing chain tension adjuster onto the engine block, then tighten the mounting bolts to 97 inch lbs. (11 Nm). Pull the pin out of the adjuster.
- Install the inner timing chain guide, making sure that the spacer is installed on the upper mounting bolt. Tighten the mounting fasteners to 97 inch lbs. (11 Nm).
- Double check that the dark blue and yellow chain pieces are still aligned with the idler and crankshaft sprocket matchmarks (respectively), and that the crankshaft timing sprocket mark is still aligned with the mark on the engine block..
- Ensure that the locating dowels of the intake and exhaust camshafts are aligned with the timing marks on the cylinder head, as shown in the accompanying illustration.
- Hold both of the camshaft sprockets and have an assistant drape the outer timing chain over them so that the blue chain pieces are aligned with the matchmarks on the sprockets. It may be necessary to turn the chain around if the blue marks are too far apart. Position the sprockets and chain so that the chain is engaged on the underside of the idler sprocket, and the yellow chain link is aligned with the mark (arrow) on the idler sprocket. Once the chain is properly positioned with respect to all three sprockets, install the intake and exhaust camshaft sprockets on their respective camshafts.
The camshaft sprockets do not have a specific direction of orientation; either side of both sprockets may be positioned so that they face away from the camshaft.
- Install the camshaft sprocket retaining bolts finger-tight, then secure the camshafts (one at a time) with an open end wrench. Tighten both sprocket retaining bolts to 44 ft. lbs. (60 Nm).
- With the plunger of the outer timing chain tension adjuster fully depressed into the adjuster, insert a push-pin into the latch and adjuster body. With the push-pin installed, the plunger should not come out of the adjuster body.
- Install the outer timing chain tension adjuster, along with a new gasket, onto the cylinder head. Tighten the mounting bolts to 97 inch lbs. (11 Nm) and the idler sprocket nut to 33 ft. lbs. (45 Nm).
- Pull the push-pin out of the adjuster body to tension the outer timing chain.
- Rotate the crankshaft clockwise two full revolutions, and realign the crankshaft sprocket timing mark with the mark on the engine block. Ensure that the camshaft and idler sprocket marks are still aligned with the timing marks on the engine block and cylinder head.
- Lubricate the timing chains, guides, tensioners, adjusters, and sprockets with clean engine oil.
- Install the timing chain cover and all related engine components.