TM 5-3895-346-14
CYLINDER HEAD
ENGINE OVERHAUL
7.
After the head is in place, remove the guide studs and chain hoist and install the remaining bolts,
running all bolts down snug tight with a speed handle (15-20 lb ft or 20-27 Nm torque). However, before
tightening the bolts, loosen the lifter bracket-to-cylinder head attaching bolts, otherwise the head may be
prevented from seating properly on the cylinder block. A similar condition could exist if the exhaust manifold is
attached to the cylinder head. Clearance must be assured between the exhaust manifold and the bosses on
the cylinder block. On some engine models, these bosses serve as a rest for the exhaust manifold after the
cylinder head has been installed on the cylinder block.
8.
Tighten the bolts to 170-180 lb ft (231-244 Nm) torque in 50 lb ft (68 Nm) increments with a torque
wrench, as in the sequence shown in Fig. 7. Repeat the tightening sequence at least once, because the first
bolts tightened in the sequence tend to lose significant clamp load during tightening of the remaining bolts.
Apply a steady pressure for 2 or 3 seconds at the prescribed torque to allow the bolts to turn while the gaskets
yield to their final designed thickness. Begin on the cam follower side of the head to take up tension in the
push rod springs. Tighten the bolts to the high side of the torque specification, but do not exceed the limit or
the bolts may stretch beyond their elastic limits. Attempting to tighten the bolts in one step may result in trouble
and consequent loss of time in diagnosis and correction of difficulties, such as compression leaks, when the
engine is put into operation.
CAUTION
Tightening the cylinder head bolts will not correct a leaking compression gasket or
seal. The head must be removed and the damaged gasket or seal replaced.
9.
Cover the oil drain holes in the cylinder head to prevent foreign objects from falling into the holes.
10.
If the fuel injectors were not previously installed, refer to Fuel Injector and install them at this time.
11.
Tighten the rocker arm bracket bolts to 50-55 lb ft (68-75 Nm) torque.
Figure 7 . Cylinder Head Bolt Tightening Sequence
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