70-00-00 Standard Procedures
1. General
This chapter contains standard procedures and data about the fasteners used for the E4 engine.
A. Safetying methods
(1) Safety wiring
Safety wiring is a method of locking together two or more units so that any tendency of one to loosen
is counteracted by the tightening of the wire.
Safety wiring can be used around bolt heads or nuts where no other means of locking them are
available, areas of movement and vibration.
A bolt that is correctly locked holds the fastener in place and pulls it tighter.
Lock-wire prevents the fasteners from becoming loose. It comes in different thickness and alloys for
different applications.
Thin lock-wires are not very strong, but easier to work with and can be bended around light bolts
where the wire does not have a lot of pull on it.
Thicker lock-wires are extremely strong, but very stiff and difficult to bend and tighten around a tight
radius.
(2) Torque
The preload level determines the capacity of a bolted joint. Therefore, it is important to determine the
amount of preload torque tension necessary in a joint in order to absorb the reciprocating force and
tolerate the force generated by moving parts.
(3) Installation of helical threaded inserts
The helical threaded inserts are used to repair the damaged and worn threads and to safety the
fasteners against vibration or shock loosening. Helicoil inserts are precision formed coils of stainless
steel. After installation, the insert provides permanent screw threads.
B. Standard Torque Values
Use the following standard torque values where no specific values are given.
When you use self-locking nuts, add the safety torque (friction torque or braking torque) to
the table values. Set this value on the dial of the torque meter before you tighten the nut.
If a bolt has an additional torque due to shaft friction, add this torque value to the table value. Set
this calculated value on the dial of the torque meter before you tighten the bolt.
Lubricate threads unless specified differently.
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