,&$$apter 2 Part A 2.6L four-cylinder engine
ZA- 13
WEAR ZONE
1 I
t-ACTUAL WEAR
13.10 Measure the height of the camshaft lobes at the wear zone
and unworn area, then subtract the wear zone measurement from
the unworn area measurement to get the actual wear-compare
the wear to the limit listed in this Chapter’s Specifications
14.7 Before removina the
camshaft sprocket, position
the tensioner locking tool
between the chain, at the
tensioner - be sure the tool
has a cord or wire attached to
the end of it so it can be easily
removed after the job - if the
tool is not available, a block of
wood and a length of
mechanic’s wire will also work
‘4
cl
If there’s wear-on the toe or the ramp, replace the camshaft, but first
try to find the cause of the wear. Look for abrasive substances in
theoiland inspect the oil pump and oil passages for blockage. Lobe
wear is usually caused by inadequate lubrication or dirty oil.
Using a micrometer, calculate the lobe wear (see illustration). If
the lobe wear is greater than listed in this Chapter’s Specifications,
replace the camshaft.
11 Inspect the rocker arms forwear, galling and pitting of the contactsur-
faces.
12 If any of the conditions described above are noted, the cylinder head
is probably getting insufficient lubrication or dirty oil, so make sure you
track2own the cause of this problem (low oil level, low oil pump capacity,
clogged oil passage, etc.) before installing a new head, camshaft or rocker
arms.
Ins talla tion
Refer to illustration 13.14
13 Thoroughly clean the camshaft, the bearing surfaces in the head and
caps and the rocker arms. Remove all sludge and dirt. Wipe off all compo-
nents with a clean, lint-free cloth.
14 Lubricate the camshaft bearing surfaces in the head and the bearing
journals and lobes on the camshaft with assembly lube or moly-base
grease. Carefullylowerthecamshaftinto position with thedowel pin point-
ing up (see illustration). Caution: Failure to adequate/y lubricate fhe
camshaftand related components can cause serious damage to bearing
13.14 Install the camshaft with the dowel pin pointing up
and friction surfaces during the first few seconds after engine start-up,
when the oil pressure is low or nonexistent.
15 Coat the outsidediameterof the circular plug with RTVsealant. Install
the plug to the rear of the cylinder head.
16 Apply a thin coat of assembly lube ormoly-base grease tottie bearing
surfaces of the camshaft bearing caps.
17 Install the rocker arm shaft assembly. Tighten the camshaft bearing .
cap bolts l/4-turn at a time, starting from the middle and working out to the
ends, until the torque listed in this Chapter’s Specifications is reached.
16 Install the camshaft sprocket and timing chain and related compo-
nents (see Section 10). If you suspended the camshaft sprocket out the
way and didn’t disturb the timing chain or sprockets, the valve timing
should still be correct. Rotate the camshaft as necessary to reattach the
sprocket to the camshaft. If the timing was disturbed, align the sprockets
and install the chain as described in section IO.
19 Remove the spark plugs and rotate the crankshaft by hand to make
sure the valve timing is correct. After two revolutions, the timing marks on
the sprockets should still be aligned. If they’re not, re-index the timing
chain to the sprockets (see Section’lO). Note: Ifyoufeelresistance while
rotating the crankshaft, stop immediately and check the valve timing by
referring to Section IO.
20 Adjust the valve clearances as described in Chapter 1.
21 lnstallthesemi-circularplug tothefrontofthecylinderheadandapply
sealant to the top of the semi-circular plug.
22 Install the valve cover and gasket.
23 The remainder of installation is the reverse of removal.
14 Cylinder head - removal and installation
Caution: Allow the engine to coolcompletelybefore beginning thisproce-
dure.
Removal
Refer to illustrations 14.7and 14.3
1 Position the number one piston at Top Dead Center (see Section 3).
2 Disconnect the negative cable from the battery.
3 Drain the cooling system and remove the spark plugs (see Chap-
ter 1).
4 Remove the intake and exhaust manifold (see Sections 7 and 8).
Note: Ifyou’re only replacing the cylinderheadgasket, itisn’tnecessaryto
remove the manifolds. lfyou leave the manifolds attached, you may need
an assistant to he/p lift the head off the engine, since it !&ill be quite heavy
5 Remove the valve cover (see Section 4).
6 Remove the distributor (see Chapter 5) including the cap and wires.
7 Remove the silent shaft chain and sprockets (see Section 9) and the
timing chain and sprocket (see Section 10). Note: It is possible to use a
tensioner locking
tool(see illusfration) to hold the chain andfensiqnerin
plate while the cylinder head is off the engine. This will save time you by
1~
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