Attention! Since 1995, the 5.0 and 5.7 liter V6 and V8 engines have had a single-use plastic front cover. The cover after removal is changed to prevent oil leakage. On 7.4 liter V8 engines since 1996, the front cover gasket and the cover itself are reusable. The gasket on these engines is changed only when damage is detected on it.
1. Remove the coolant pump.
2. Remove the bolts (see photo) and remove the drive belt pulley.
3. Set the piston of the 1st cylinder to the TDC of the compression stroke. Then turn the crankshaft 1 turn.
Attention! After completing this procedure, the crankshaft is not allowed to rotate until all drive sprockets are in place.
4. Turn away a bolt of fastening of a forward flywheel and press a screw remover a forward flywheel from a toe of the crankshaft (see photo).
5. On most 5.0L and 5.7L V6 and V8 engines, the timing cover is removed only after the oil pan has been removed. The sump bolts should be loosened and the sump lowered slightly. If the pallet, dismantled in this way, remains loose for a long time, the gasket will lose its elasticity. In this case, the pallet should be removed and the gasket replaced.
6. To access the timing chain cover, remove the power steering pump, alternator and air conditioning compressor. Do not disconnect hoses/wires, move units aside and secure. The removal procedure is discussed in Chapter 3, 5 and 10. Remove the support bracket at the front of the engine (see photo).
7. Remove the bolts and remove the timing chain cover from the cylinder block. If the cap is stuck and cannot be removed, pry open the seal with a dull knife or spatula.
Attention! On a part of the engines, the setting scale is fastened with cover bolts. Pay attention to the orientation of the scale and set it to its original position when reassembling.
8. On 7.4 liter engines, push the cover forward and cut off the front of the engine pan gasket on both sides, then remove the cover.
9. On models from 1995, remove the crankshaft position sensor ring.
Attention! On engines 7.4, a special puller is required to remove the ring, the removed ring is replaced with a new one.
10. Check timing chain deflection. If the deflection exceeds 15.5 mm, replace the chain with sprockets.
11. On all engines except 1994 V6 engines, remove three bolts, or two bolts and a nut (on 4.3L V6 models from 1994) fastening the camshaft sprocket and remove the camshaft sprocket together with the chain.
Attention! On 4.3L V6 engines since 1994, the balance shaft drive gear remains on the camshaft, and the driven gear also remains on the balance shaft. The crankshaft sprocket can be pressed with a puller. If traces of oil leakage are found on the oil seal in the timing chain cover, replace the oil seal.
12. Clear a cover and a place of adjoining of a cover on the block of cylinders.
13. Check the condition of the flange portion of the cover, especially around the bolt holes where there may be bent areas. If necessary, straighten the cover flange on a wooden board.
14. If new parts are being installed, make sure the keyway in the sprocket is aligned with the crankshaft key.
Attention! The timing chain is changed complete with crankshaft and camshaft sprockets. The sprocket is pressed onto the crankshaft toe by tightening the front flywheel bolt, or by hammering through the soft spacer. It is not allowed to press the sprocket when resistance is felt (for example, in case of a skew).
15. Install the chain on the camshaft sprocket, then turn the sprocket so that the alignment mark is exactly at 6 o'clock (see photo). Engage the chain with the crankshaft sprocket and install the sprocket onto the camshaft. If necessary, turn the camshaft so. so that the pin goes into the hole in the sprocket and the alignment mark points to 6 o'clock.
Attention! When installing the chain and sprocket, the piston of the 4th cylinder on a V6 engine, or the piston of the 6th cylinder on a V8 engine, must be at TDC on the compression stroke.
16. Lubricate the threads of the 6th camshaft sprocket with a fixing compound, tighten the bolts to the specified torque. Lubricate the chain with clean engine oil.
17. Lubricate the U-channel at the bottom of the timing chain cover with RTV sealant.
18. On 7.4 liter V8 engines, cut the tabs from the new oil pan gasket, glue them with sealant to the bottom split surface of the cover. Apply a bead of 3 mm RTV sealant to the joint between the sump and the cylinder block on both sides.
19. On V6 and V8 5.0 and 5.7 liter engines, a one-piece pan gasket is used to seal the junction of the cover and the engine, the condition of which should be checked. If cracks or deformations are found, replace the gasket.
20. Apply a light coat of RTV sealant to both sides of the new cover gasket, install the gasket in place on the cylinder block. The gasket must be held on by pins and sealant.
21. Install the timing chain cover on the cylinder block, tighten the pan bolts.
22. If the oil pan was removed on a V6 engine, or 5.0 or 5.7 liter V8 engines, reinstall it. If the pan bolts have been loosened, then tighten the bolts by first lifting the oil pan and resting it against the timing chain cover.
23. Torque tighten the timing chain cover bolts.
24. Lubricate the lip of the front flywheel oil seal with molybdenum grease or clean engine oil and install the flywheel in place, aligning the groove with the key.
If the front flywheel is not put on by hand on the crankshaft, then press it on by tightening the flywheel mounting bolt through a washer of a sufficiently large diameter. Then remove the washer and tighten the bolt to the specified torque.
25. Further assembly is carried out in the reverse order.