01-14
Basic Enaine
01-14
CLEANING AND INSPECTION (Continued)
Check each spring for squareness, using a steel square
and a flat surface. Stand the spring and square on end on
the flat surface. Slide the spring up to the square. Revolve
the spring slowly and observe the space between the top
coil of the spring and the square. The out-of-square limits
are 2 mm (5/64 inch).
Follow the same procedure to check new valve springs
before installation.
Make certain the proper spring (color
coded) is installed.
CLOSED
COIL END
DOWNWARD
NOT MORE
THAN 2.0 MM (5/64”)
Tappets
Cleaning
Thoroughly clean the tappets in cleaning solvent and wipe
them with a clean lint-free cloth.
Inspection
Check th? tappets for wear or scores. Check the bottom
end of tappet to make sure that it has a slight convex.
Replace tappets that are scored, worn, or if the bottom is
not smooth. If the bottom surface is worn flat, it may be
used with the original camshaft only.
Timing Chain and Sprockets
Cleaning
Clean a!’ parts in solvent and dry them with compressed
air. Lubricate the timing chain with engine oil before
installing it on the sprockets.
Inspection
Inspect the chain for broken links. Inspect the sprockets
for cracks and worn or damaged teeth. Replace all the
components of the timing chain and sprocket assembly,
if any o,le item needs replacement.
Camshaft
Cleaning
Clean the camshaft in solvent and wipe it dry.
Inspection
Inspect the camshaft lobes for scoring and signs of
abnormal wear. Lobe pitting except in the general area
of the lobe toe is not detrimental to the operation of the
camshaft; therefore, the camshaft should not be replaced
unless the lobe lift loss has exceeded specifications or
pitting has occurred in the lobe lift area.
The lift of the camshaft lobes can be checked with the
camshaft installed in the engine or on centers. Refer to
Camshaft Lobe Lift.
To measure the camshaft lobe lift proceed as follows:
1.
Measure distance between the major (A-A) and minor
(B-B) diameters of each cam lobe with a Vernier
caliper and record the readings. The difference in the
readings on each cam diameter is the lobe lift.
t t
NO PITTING
6.35 MM 6.35 MM
f
ALLOWED IN
(l/4”),
(l/4”)
THIS AREA
DIMENSION A
DIMENSION B
THE CAM LOB
MINUS
EQUAL
IE LIFT
A
2.
If the readings do not meet specification, replace the
camshaft.
Camshaft Bores
Inspection
Check camshaft bores for size, taper, roundness, runout,
and finish. If any of these dimensions exceeds the limits
given in Specifications, install new camshaft bearings.
Crankshaft
Cleaning
Handle the crankshaft with care to avoid possible fractures
or damage to the finished surfaces. Clean the crankshaft
with solvent, then blow out all oil passages with
compressed air.
Inspection
Inspect the main and connecting rod journals for cracks,
scratches, grooves or scores. Inspect the crankshaft oil
seal surface for nicks, sharp edges or burrs that might
damage the oil seal during installation or cause premature
seal wear.
Measure the diameter of each journal in at least four places
to determine an out-of-round, taper or undersize condition.
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