Tightening Procedures
Generally, when installing a part with several bolts, nuts or screws, they should all be started in their holes and tightened to a snug fit, evenly and in a cross pattern. This is to avoid distortion of the part and/or gas or oil leakage. Conversely, bolts, nuts, or screws, should all be loosened (in sequence if specified) by about a quarter of a turn and then removed.
Where there is a tightening sequence specified in this Service Manual, the bolts, nuts, or screws must be tightened in the order and by the method indicated.
Torque wrench setting figures given in this manual must be observed. The torque tools used must be of accurate calibration.
Torque Tolerance
Torque | Tolerance |
0 Nm to 25 Nm | +/- 10% |
26 Nm to 100 Nm | +10% -0% |
101 Nm to 200 Nm | +10% -0% |
Locking devices, where specified, must be fitted. If the efficiency of a locking device is impaired during removal it must be renewed.
This applies particularly to micro-encapsulated and patch locked fixings which must always be replaced if disturbed.
Where necessary, the text in this manual will indicate where such a fixing is used.