Renault Laguna III, Manual

Page: 3090 / 3699

01D
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5
MECHANICAL INTRODUCTION
Tightening torques: General information
01D
For example:
- 1 torque wrench 4 - 40 N.m ,
- 1 torque wrench 20 - 100 N.m ,
- 1 torque wrench 80 - 400 N.m ,
- 1 angle measurement disc.
The torque wrenches used must comply with the ISO
6789 standard. They must be calibrated regularly fol-
lowing the supplier's recommendations using the ap-
propriate procedures.
VI - PRECAUTIONS WHEN USING A CLICK TYPE
TORQUE WRENCH
A click type torque wrench is a manual tightening tool.
The trigger mechanism causes a break or disengage-
ment of the wrench past a force threshold.
This threshold depends on the setting of the wrench
but also depends on the way the wrench is handled.
When used following best practises, the accuracy of
the tightness when using a click type torque wrench is
±
15%.
The instructions to be observed are:
- Place the hand in the centre of the handle. An incor-
rectly positioned hand on the handle will alter the trig-
ger threshold.
- Pull the wrench gently and steadily, without applying
any torsion. Excessive tightening speed as well as jerk-
iness are major causes of overtightening. Any torsion
applied to the wrench will alter the trigger threshold.
- Hold the wrench on the bolt using a minimum of effort.
Any effort applied to the wrench head will alter the trig-
ger threshold.
- Apply the tightening effort perpendicular to the mount-
ing observing a tolerance of
±
15˚ relative to the per-
pendicularity. If the wrench is not perpendicular to the
mounting axis, this will result in insufficient tightening.
- Stop tightening as soon as the wrench is triggered.
Continued tightening after the wrench is triggered will
lead to overtightening.
120740
( 6 ) lever arm
120741
120742