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Camshafts and hydraulic tappets - removal, inspection and refitting
In-car engine repair procedures / Camshafts and hydraulic tappets - removal, inspection and refitting


Removal
1 Release the tension from the timing belt as described in Section 10, paragraphs 1 to 14.

2 Either remove the timing belt completely (Section 10, paragraphs 15 and 16) or slip it off the camshaft toothed pulleys, taking care not to twist it too sharply; use the fingers only to handle the belt. Cover the belt, and secure it so that it is clear of the working area. Do not rotate the crankshaft until the timing belt is refitted.

3 Unfasten the pulley bolts as described in Section 10, paragraphs 18 and 21, and withdraw the pulleys; while both are the same and could be interchanged, it is good working practice to mark them so that each is refitted only to its original location (see illustration).

13.3 Using forked holding tool while camshaft toothed pulley bolt is
13.3 Using forked holding tool while camshaft toothed pulley bolt is slackened

4 Working in the sequence shown, slacken progressively, by half a turn at a time, the camshaft bearing cap bolts (see illustration).

Work only as described, to release gradually and evenly the pressure of the valve springs on the caps.

13.4 Camshaft bearing cap slackening sequence
13.4 Camshaft bearing cap slackening sequence

Note: View from front of vehicle, showing bearing cap numbers

5 Withdraw the caps, noting their markings and the presence of the locating dowels, then remove the camshafts and withdraw their oil seals. The inlet camshaft can be identified by the reference lobe for the camshaft position sensor; therefore, there is no need to mark the camshafts (see illustrations).

13.5A Note locating dowels when removing camshaft bearing caps
13.5A Note locating dowels when removing camshaft bearing caps

13.5B Inlet camshaft has lobe for camshaft position sensor
13.5B Inlet camshaft has lobe for camshaft position sensor

6 Obtain sixteen small, clean containers, and number them 1 to 16. Using a rubber sucker, withdraw each hydraulic tappet in turn, invert it to prevent oil loss, and place it in its respective container, which should then be filled with clean engine oil (see illustrations).

Do not interchange the hydraulic tappets, or the rate of wear will be much increased. Do not allow them to lose oil, or they will take a long time to refill on restarting the engine, resulting in incorrect valve clearances.

13.6A Removing hydraulic tappets
13.6A Removing hydraulic tappets

13.6B Hydraulic tappets must be stored as described in text
13.6B Hydraulic tappets must be stored as described in text

Inspection
7 With the camshafts and hydraulic tappets removed, check each for signs of obvious wear (scoring, pitting etc) and for ovality, and renew if necessary.

8 Measure the outside diameter of each tappet (see illustration) - take measurements at the top and bottom of each tappet, then a second set at right-angles to the first; if any measurement is significantly different from the others, the tappet is tapered or oval (as applicable) and must be renewed. If the necessary equipment is available, measure the inside diameter of the corresponding cylinder head bore. Compare the measurements obtained to those given in the Specifications Section of this Chapter; if the tappets or the cylinder head bores are excessively worn, new tappets and/or a new cylinder head will be required.

13.8 Use a micrometer to measure diameter of hydraulic tappets
13.8 Use a micrometer to measure diameter of hydraulic tappets

9 If the engines valve components have sounded noisy, particularly if the noise persists after initial start-up from cold, there is reason to suspect a faulty hydraulic tappet.

Only a good mechanic experienced in these engines can tell whether the noise level is typical, or if renewal of one or more of the tappets is warranted. If faulty tappets are diagnosed, and the engines service history is unknown, it is always worth trying the effect of renewing the engine oil and filter (see Chapter 1), using only good-quality engine oil of the recommended viscosity and specification, before going to the expense of renewing any of the tappets - refer also to the advice in Section 1 of this Chapter.

10 Visually examine the camshaft lobes for score marks, pitting, galling (wear due to rubbing) and evidence of overheating (blue, discoloured areas). Look for flaking away of the hardened surface layer of each lobe (see illustration). If any such signs are evident, renew the component concerned.

13.10 Check the cam lobes for pitting, wear and score marks - if scoring is
13.10 Check the cam lobes for pitting, wear and score marks - if scoring is excessive, as is the case here, renew the camshaft

11 Examine the camshaft bearing journals and the cylinder head bearing surfaces for signs of obvious wear or pitting. If any such signs are evident, renew the component concerned.

12 Using a micrometer, measure the diameter of each journal at several points (see illustration). If the diameter of any one journal is less than the specified value, renew the camshaft.

13.12 Measure each journal diameter with a micrometer - if any journal
13.12 Measure each journal diameter with a micrometer - if any journal measures less than the specified limit, renew the camshaft

13 To check the bearing journal running clearance, remove the hydraulic tappets, use a suitable solvent and a clean lint-free rag to clean carefully all bearing surfaces, then refit the camshafts and bearing caps with a strand of Plastigage across each journal (see illustration).

13.13A Lay a strip of Plastigage on each camshaft journal
13.13A Lay a strip of Plastigage on each camshaft journal

Tighten the bearing cap bolts to the specified torque wrench setting (do not rotate the camshafts), then remove the bearing caps and use the scale provided to measure the width of the compressed strands (see illustration).

13.13B Compare the width of the crushed Plastigage to the scale on the
13.13B Compare the width of the crushed Plastigage to the scale on the envelope to determine the running clearance

Scrape off the Plastigage with your fingernail or the edge of a credit card - dont scratch or nick the journals or bearing caps.

14 If the running clearance of any bearing is found to be worn to beyond the specified service limits, fit a new camshaft and repeat the check; if the clearance is still excessive, the cylinder head must be renewed.

15 To check camshaft endfloat, remove the hydraulic tappets, clean the bearing surfaces carefully, and refit the camshafts and bearing caps. Tighten the bearing cap bolts to the specified torque wrench setting, then measure the endfloat using a DTI (Dial Test Indicator, or dial gauge) mounted on the cylinder head so that its tip bears on the camshaft right-hand end.

16 Tap the camshaft fully towards the gauge, zero the gauge, then tap the camshaft fully away from the gauge, and note the gauge reading. If the endfloat measured is found to be at or beyond the specified service limit, fit a new camshaft and repeat the check; if the clearance is still excessive, the cylinder head must be renewed.

Refitting
17 On reassembly, liberally oil the cylinder head hydraulic tappet bores and the tappets (see illustration). Note that if new tappets are being fitted, they must be charged with clean engine oil before installation. Carefully refit the tappets to the cylinder head, ensuring that each tappet is refitted to its original bore, and is the correct way up. Some care will be required to enter the tappets squarely into their bores.

13.17 Oil liberally when refitting hydraulic tappets
13.17 Oil liberally when refitting hydraulic tappets

18 Liberally oil the camshaft bearings and lobes (see illustration).

13.18A Apply engine assembly lubricant or molybdenum disulphide-based grease
13.18A Apply engine assembly lubricant or molybdenum disulphide-based grease to the cam lobes and journals before refitting a camshaft

Ensuring that each
camshaft is in its original location, refit the camshafts, locating each so that the slot in its left-hand end is approximately parallel to, and just above, the cylinder head mating surface (see illustration).

13.18B Use camshaft position sensor lobe to identify inlet camshaft on
13.18B Use camshaft position sensor lobe to identify inlet camshaft on refitting - locate camshafts as described in text

19 Ensure that the locating dowels are pressed firmly into their recesses, and check that all mating surfaces are completely clean, unmarked and free from oil. Apply a thin film of suitable sealant (Ford recommend Loctite 518) to the mating surfaces of each camshafts right-hand bearing cap (see illustration). Referring to paragraph 6 of Section 12, some owners may wish to fit the new camshaft oil seals at this stage.

13.19 Apply sealant to mating surface of camshaft right-hand bearing caps
13.19 Apply sealant to mating surface of camshaft right-hand bearing caps

20 All camshaft bearing caps have a singledigit identifying number etched on them (see illustration). The exhaust camshafts bearing caps are numbered in sequence 0 (right-hand cap) to 4 (left-hand cap), the inlets 5 (righthand cap) to 9 (left-hand cap); see illustration 13.21B for details. Each cap is to be fitted so that its numbered side faces outwards, to the front (exhaust) or to the rear (inlet).

13.20 Etched marks on camshaft bearing caps must be arranged as shown, and
13.20 Etched marks on camshaft bearing caps must be arranged as shown, and face outwards

21 Ensuring that each cap is kept square to the cylinder head as it is tightened down, and working in the sequence shown, tighten the camshaft bearing cap bolts slowly and by one turn at a time, until each cap touches the cylinder head (see illustrations). Next, go round again in the same sequence, tightening the bolts to the first stage torque wrench setting specified, then once more, tightening them to the second stage setting. Work only as described, to impose gradually and evenly the pressure of the valve springs on the caps.

Fit the camshaft aligning tool; it should slip into place as described in paragraph 10 of Section 10 (see illustration).

13.21A Keep caps square to cylinder head at all times when tightening down
13.21A Keep caps square to cylinder head at all times when tightening down

13.21B Camshaft bearing cap tightening sequence
13.21B Camshaft bearing cap tightening sequence

Note: View from front of vehicle - locate bearing caps according to etched numbers, aligned as described in text

13.21C Fit camshaft aligning tool to set TDC position . . .
13.21C Fit camshaft aligning tool to set TDC position . . .

22 Wipe off all surplus sealant, so that none is left to find its way into any oilways. Follow the sealant manufacturers instructions as to the time needed for curing; usually, at least an hour must be allowed between application of the sealant and starting the engine.

23 If using Fords recommended procedure, fit new oil seals to the camshafts as described in paragraph 5 of Section 12.

24 Using the marks and notes made on dismantling to ensure that each is refitted to its original camshaft, refit the toothed pulleys to the camshafts, tightening the retaining bolts loosely (see illustration). Slip the timing belt back onto the pulleys (refer to paragraph 21 of Section 10) and tighten the bolts securely - use the forked holding tool described in paragraph 18 of Section 10.

13.24 . . . while camshaft toothed pulleys are refitted
13.24 . . . while camshaft toothed pulleys are refitted

25 The remainder of the reassembly procedure, including checking the camshaft alignment (valve timing) and setting the timing belt tension, is as described in paragraphs 17 to 27 of Section 10.


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