Jeep UNIVERSAL CJ-2A - Page 33

D
L4-134 ENGINE
tool C-482, compress the valve springs on those
valves which are in the closed position. (valve seated
against cylinder block). Remove the valve spring
retainer locks, retainer, valve, and spring. Close the
other valves by rotating the camshaft and repeat
the above operation for the other valves in the same
manner. When lifting out the valves, either tag
them or place them in a rack to indicate the loca-
tion where each was removed from the cylinder
block. If a valve sticks in the guide and cannot be
easily lifted out, pull the valve upward as far as
possible and remove the spring. Lower the valve
and remove any carbon deposits from the valve
stem. This will permit removal of the valve.
D-25. Remove Camshaft
a. Push the valve tappets into the cylinder block
as far as possible so the ends of the tappets are not
in contact with the camshaft.
b. Secure each tappet in the raised position by
installing a common clip-type clothes pin on the
shank of each tappet or. tie them up in the valve
chamber.
c. Remove the camshaft thrust plate attaching
screws, thrust plate and spacer on engines s::>
equipped.
d. Pull the camshaft forward out of the cylinder
block using care to prevent damage to the camshaft
bearing surfaces.
e. To remove a camshaft with the engine in the
vehicle, first drain the radiator and cylinder block.
Then remove the radiator, grille, cylinder head,
manifolds, valves and valve springs, fuel pump,
oil pump, oil pan, crankshaft pulley, fan, nuts from
front engine supports, timing cover, camshaft
sprocket or gear, and thrust plate. Then proceed
with steps a, b and c above. Then place· a jack with
a block of wood under the crankcase and raise the
front of the engine until the camshaft will clear
the frame front cross member. Then proceed with
step d above.
D-26. Remove Valve Tappets
Remove the valve tappets from the bottom or
crankshaft side of the cylinder block after the cam-
shaft has been removed. Tag each tappet or. place
them. in a marked rack so they may be reassembled
in their original positions.
D-27. Remove Oil Gallery Plugs
Removetheplug at each end of the oil gallery in
the·cylinder block. This operation is only applicable
when the engine is out of the vehicle and will allow
access to the oil gaUery so it may be cleaned ..
D-28. ENGINE INSPECTION AND REPAIR
The inspection and repair procedures detailed here-
in are recommended to be followed when a com-
plete engine overM.ul is to be made with the engine
out of the vehicle. These instructions can generally
be applied individually with the engine in the
vehicle. Wl:lerever the procedure differs due . to
the engine •. being in the vehicle, the necessary
special instructions are provided. Inspection and
repair instructions are included to cover the
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cylinder block, cylinder head, crankshaft and
bearings, connecting rods and bearings, oil pump,
valves and tappets, pistons and rings, flywheel,
timing gears, and the camshaft and bearings. In
addition, fitting operations for these engine com-
ponents are included.
Important: Before the inspection and repair pro-
cedures listed below are begun, the engine serial
number must be checked for the presence of code
letters denoting undersize bearings or oversize
pistons. Refer to Par. D-2.
D-29. Cylinder Block
The cylinder block must be thoroughly cleaned,
inspected and repaired as detailed in the following
paragraphs.
D-30. Cleaning
The cylinder block may be steam cleaned or cleaned
with a suitable solvent. A scraper is recommended
to remove hard deposits, except on highly finished
surfaces. Special attention must be directed to the
cleaning of the oil passages, valve chamber, crank-
case, and cylinder walls to remove all sludge, dirt
carbon deposits. After cleaning, use air pressure to
dry the block thoroughly.
D-31. Inspection
Examine the cylinder block for minute cracks and
fractures. Rusted valve springs or evidence of rust
in the valve chamber or the cylinder walls is a good
indication of a possible crack in the block.
a. Examine all machined surfaces of the cylinder
block for burrs and scores. Check for cylinder block
distortion by placing a straight edge along the
length of the cylinder head surface of the block.
With a feeler gauge, check for clearance between
the straight edge and the block, particularly be-
tween adjacent cylinders. Maximum permissable
out of line for service is .010, [0,254 mm.].
b. Check the cylinder bores for out-of-round and
taper to determine if the bores require honing or
reboring. For detail information refer to Par. D-32.
c. If there is any reason to believe that any of the
main bearing cap dowels have been bent during
bearing cap removal, install new ones. The dowels
must fit tightly to ensure cap alignment and as they
are hardened they may be difficult to grip and re-
move. To simplify the operation, file a notch on
each side of the dowel to accommodate a pair of
diagonal cutt.ers. Using a piece of bar stock under
the diagonals for leverage, work the dowel out. Be-
fore installing a new dowel in the cylinder block,
make sure the dowel hole is clean. Start the dowel
straight in the hole, then tap the dowel lightly
with a hammer until it bottoms. ·
d. When installing beating caps, be sure to tighten
the bolts evenly in each cap to pull it into place
without bending the dowels or distortin~ the
bearing cap. .
e. Other parts of the block which require inspecc
tion. and possil:;>le repair, .but which are directly
related to otl1er engine components (such as
tappets, J:>istons, camshaft, valves,. crankshaft, and
oil pump) are covered later in this section. · ·