Camshafts and tappets/roller followers and lash adjusters — removal, inspection and installation
Caution: These engines are difficult to work on and require some special tools. On any procedure involving the timing chains, the Steps must be read carefully and disassembly must proceed using the special tools, otherwise damage to the engine will result.
Caution: Because this is an interference engine design, if the timing chain has broken, there will be damage to the valves (and possibly the pistons) and will require removal of the cylinder heads.
Caution: The timing system is complex. Severe engine damage will occur if you make any mistakes. Do not attempt this procedure unless you are highly experienced with this type of repair. If you are at all unsure of your abilities, consult an expert. Double-check all your work and be sure everything is correct before you attempt to start the engine.
Caution: 2.7L and 3.5L turbocharged models are equipped with Direct Injection (DI) and a high-pressure fuel pump. Fuel pressure in the high-pressure system on Direct Injection (Dl) systems is under extremely high pressure. Be sure to correctly perform the fuel pressure relief procedure prior to servicing any of the high-pressure fuel system components to prevent injury (see Fuel and exhaust systems).
Note: 3.5L and 3.7L Duratek engines use solid tappets (cam followers). 2.7L EcoBoost engines use roller followers and hydraulic lash adjusters.
Note: This procedure can only be done with the engine removed.
Note: Two special camshaft holding tools (manufacturer tool no. 303-1248) are required for this procedure.
Removal
1. Raise the vehicle and support it securely on jack stands.
2. Relieve the fuel pressure (see Fuel and exhaust systems).
3. Disconnect the cable from the negative battery terminal (see Engine electrical systems).
2.7L models
Note: If you’re removing the camshafts from both sides, remove the right (rear) side first.
4. Remove the high-pressure fuel pump drive (see Fuel and exhaust systems) when removing the right-side(rear) camshafts or the brake vacuum pump (see Brakes) when removing the left-side (front) camshafts.
5. Refer to Timing chains and sprockets — removal and installation and remove the timing chain (s) and camshaft VCT units.
6. Loosen then remove the front «mega- cap» mounting bolts and mega-cap first.
7. The front camshaft mega-cap must be removed first then the remaining camshaft bearing caps or possible engine damage may occur.
8. Loosen the camshaft cap mounting bolts and remove the caps.
Caution: Keep the caps in order and don’t mix them up.
9. Remove the camshafts from the cylinder head (s).
10. Remove the roller followers and lash adjusters as assemblies. Keep the follow-errs and lash adjusters in order and don’t mix them up.
11. Remove the spring clips on the camshaft roller followers and separate the lash adjusters from the rockers.
Caution: If the original components are to be reinstalled, they must be installed in their original locations 2010 and earlier 3.5L and 3.7L engines
12. Before removing the camshafts, check the valve clearances (see Valve clearance (3.5L and 3.7L engines) — check and adjustment).
13. Remove the primary timing chain and the front (left) cylinder bank VCT assembly/ camshaft sprockets/secondary timing chain (see Timing chains and sprockets — removal and installation), then remove the camshaft holding tool from the front (left) cylinder bank camshafts. Confirm that the neutral positions after the holding tool have been removed (see illustration).
10.13 Front (left) bank camshaft timing marks (keyways) in the neutral position — 2010 and earlier engines
14. Note the location of each camshaft cap. Use a marker on each cap or notes on paper or cardboard if they’re not marked.
15. Working in the order opposite that of the tightening sequence (see illustration 10.19), remove the camshaft bearing cap bolts. Remove the caps, then lift the camshafts from the cylinder head. Lay all of the parts out in order to prevent mixing them up.
16. Remove the primary timing chain and the rear (right) cylinder bank VCT assembly/ camshaft sprockets/secondary timing chain (see Timing chains and sprockets — removal and installation), then remove the camshaft holding tool from the rear (right) cylinder bank camshafts. Confirm that the camshafts are in their neutral positions after the holding tool has been removed (see illustration).
10.16 Rear (right) bank camshaft timing marks (keyways) in the neutral position — 2010 and earlier engines
17. Note the location of each camshaft cap. Use a marker on each cap, or make notes on paper or cardboard, if they’re not marked.
18. Working in the order opposite that of the tightening sequence, remove the camshaft bearing cap bolts. Remove the caps, then lift the camshafts from the cylinder head. Lay all of the parts out in order to prevent mixing them up.
2011 and later 3.5L and 3.7L models
19. Remove the primary timing chain and camshaft VCT units (see Timing chains and sprockets — removal and installation).
20. Loosen the camshaft cap and mega-cap mounting bolts and remove the caps.
Caution: Keep the caps in order and don’t mix them up. Remove the camshafts from the cylinder head.
All models
21. With the camshafts removed, the lifters can be removed using a magnet.
Caution: They must be stored in an egg carton or other divided and marked container, so they can be restored to their original locations during reassembly.
Inspection
22. After the camshafts have been removed, clean them with solvent, then inspect the bearing journals for uneven wear and pitting. If the journals are damaged, the bearing saddles in the cylinder heads and caps are probably damaged as well. The head and camshaft caps will have to be replaced.
23. Measure the bearing journals with a micrometer and compare to the Specifications in this Chapter to determine whether they are excessively worn or out-of-round.
24. Measure the camshaft lobe height and the base circle (see illustrations). The difference between the two measurements is the lobe lift (lobe height — base circle = lobe lift). Record this figure for future reference and repeat the check on the remaining camshaft lobes. Compare the results to the values listed in this Chapter’s Specifications.
10.24a Lobe lift can be obtained by measuring camshaft lobe height
10.24b. . and by measuring the camshaft base circle — the difference between the two measurements equals lobe lift
25. Inspect the camshaft lobes for heat discoloration, score marks, chipped areas, pitting and uneven wear. If the lobes are in good condition and if the lobe lift measurements are as specified, you can reuse the camshafts.
26. On 2.7L engines, check the lash adjusters and roller followers for wear (see illustrations).
10.26a On 2.7L engines, inspect the lash adjuster for signs of excessive wear or damage, such as pitting, scoring or signs of overheating (bluing or discoloration) — the areas of wear are the rocker arm pivot point (1) and the side surfaces where the lifter body contacts the cylinder head bore (2)
10.26b On 2.7L engines, check the rocker arm roller, the valve stem contact point and lash adjuster contact point
Installation 2.7L models
27. Lubricate the lash adjusters with oil and install them into their original locations.
Caution: Do not install the camshaft roller followers at this time. They will be installed later. If the followers are installed before the camshaft’s caps are tightened, the camshaft caps can become distorted when the camshafts are tightened and cause severe damage to the engine. Lubricate the camshaft bearing journals and cam lobes with moly-based grease or camshaft installation lubricant.
28. Position the camshafts in the cylinder head in their neutral positions (see illustrations).
10.28a When installing the front (left) side cylinder head camshafts, position the D-slot pins like this — 2.7L engine
10.28b When installing the rear (right) side cylinder head camshafts, position the D-slot pins like this — 2.7L engine
29. Apply a small 1 mm bead of RTV sealant to the rear camshaft cap at the inner corners, then install the camshaft cap and remaining camshaft caps with bolts, loosely tightening the cap bolts at this time.
30. Install the front «mega-cap» and bolts and loosely tighten the mega-cap bolts at this time.
31. Tighten all the camshaft bolts, in sequence (see illustrations), to the torque listed in this Chapter’s Specifications.
10.31a Front (left) camshaft bearing cap tightening sequence 2.7L engine
10.31b Rear (right) camshaft bearing cap tightening sequence -2.7L engine
32. Install the camshaft holding tools to the left camshafts, then install the VCT units.
33. Install the timing chains (see Timing chains and sprockets — removal and installation) but do not install the valve covers.
34. Starting with the front cylinder, rotate the crankshaft pulley clockwise until the cylinder camshaft lobes are pointing upwards.
35. Install special service tool 303-1633 and 303-1633-01 over the camshaft and onto the top of the valve springs. Tighten the knob on the tool clockwise to depress the valve and spring.
36. Lubricate the roller follower with clean engine oil then insert the follower, making sure the spring clip on the follower clips onto the lash adjuster. Once the follower and lash adjuster are assembled, rotate the knob on the tool counterclockwise to slowly release the valve and spring.
37. Repeat Steps 35 and 36 for the remaining roller followers.
All 3.5L and 3.7L engines
38. Rotate the crankshaft counterclockwise and position the keyway in the 9 o’clock position (this is the neutral position).
Caution: The crankshaft must remain in this position until the camshafts are installed and the valve clearances are checked and, if necessary, adjusted.
39. Lubricate the lifters with clean engine oil and reinstall them in their original locations. If any valve clearances were out-of-specification, replace the lifter (s) with new ones of the proper thickness to achieve the desired clearance.
40. At the front of each camshaft, there are two grooves to hold seals. Obtain new seals and install them in the camshaft grooves.
2010 and earlier 3.5L and 3.7L engines
41. Lubricate the camshafts and bearing saddles in the cylinder head for the front (left) cylinder bank with clean engine oil or camshaft installation lube. Set the camshafts in the cylinder head, making sure they are in their neutral positions (see illustration 10.13).
42. Lubricate the friction surfaces of the front bank camshaft bearing caps with clean engine oil or camshaft installation lube and install them in their proper positions. Install the bolts and tighten them, in the proper sequence (see illustration), to the torque listed in this Chapter’s Specifications.
10.42 Front (left) bank camshaft bearing cap tightening sequence — 2010 and earlier engines
43. Lubricate the camshafts and bearing saddles in the cylinder head for the rear (right) cylinder bank with clean engine oil or camshaft installation lube. Set the camshafts in the cylinder head, making sure they are in their neutral positions (see illustration 10.16).
44. Lubricate the friction surfaces of the rear bank camshaft bearing caps with clean engine oil or camshaft installation lube and install them in their proper positions. Install the bolts and tighten them, in the proper sequence (see illustration), to the torque listed in this Chapter’s Specifications.
10.44 Rear (right) bank camshaft bearing cap tightening sequence — 2010 and earlier engines
45. Check and if necessary, adjust the valve clearances (see Four-cylinder engine).
Note: Since the crankshaft is in its neutral position, the camshafts can be turned without the danger of the valves contacting the pistons. Insert a bolt into the front of the camshaft to turn it.
46. Return the camshafts to their positions shown in illustrations 10.13 and 10.16, then install the camshaft holding tools.
2011 and later 3.5L and 3.7L models
Note: The split where the ends of each seal come together must face UP (12 o’clock position) on the camshafts when they are installed.
47. Lubricate the camshaft bearing journals and cam lobes with moly-based grease or camshaft installation lubricant.
48. Position the camshafts in the cylinder head in their neutral positions (see illustrations).
10.48a When installing the rear (right) bank cylinder head camshafts, position the dowel pins like this — 2011 and later models
10.48b When installing the left (front) bank cylinder head camshafts, position the dowel pins like this -2011 and later models
49. Install the camshaft bearing caps (in their original locations), and tighten the bolts, in sequence (see illustration), to the torque listed in this Chapter’s Specifications.
10.49 Camshaft bearing cap tightening sequence — 2011 and later models
50. Recheck the valve clearances (see Valve clearance (3.5L and 3.7L engines) — check and adjustment). Since the crankshaft is in the neutral position, the camshafts can be turned without the valves contacting the pistons.
51. Remove the camshaft cap bolts that secure the valve train oil tubes. Remove the oil tubes.
52. Rotate the camshafts to position the dowel pins in their proper positions for installing the VCT units and secondary timing chains (see illustrations). Install the camshaft holding tools.
10.52a Rotate the left (front) bank cylinder head camshafts so the dowel pins are positioned like this (TDC position), then install the camshaft holding tool — 2011 and later 3.5L/3.7L models
10.52b Rotate the right (rear) bank cylinder head camshafts so the dowel pins are positioned like this (TDC position), then install the camshaft holding tool — 2011 and later 3.5L/3.7L models
All models
53. Install the VCT units (see Timing chains and sprockets — removal and installation).
54. Rotate the crankshaft clockwise to position the keyway in the 11 o’clock position.
55. Install the primary timing chain (see Timing chains and sprockets — removal and installation).
56. Reinstall the valve train oil tubes and tighten the bearing cap bolts to the torque listed in this Chapter’s Specifications.
57. The remainder of installation is the reverse of removal.
58. Before starting and running the engine, refill the cooling system, change the oil and install a new oil filter (see Tune-up and routine maintenance).