1.2 Tightening specifications
IMPORTANT:
Mismatched or incorrect fasteners can result in damage, malfunction, or personal injury. Take care to avoid
mixing metric dimensioned fasteners and inch dimensioned fasteners.
Exceptions to these torque values are given in the Service Manual if necessary.
Prior to the installation of any hardware, make sure the components are in near new condition. Bolts and
threads must not be worn or damaged. Threads must not have burrs or nicks. Hardware must be free of
rust and corrosion. Clean the hardware with a noncorrosive cleaner.
Do not lubricate the fastener threads except for the rust preventive. The rust preventive should be applied
by the supplier of that component for the purposes of shipping and storage. Other applications for
lubricating components may also be specified in the Service Manual.
1.2.1 Constant torque hose clamp
Because of extreme temperature changes, the hose will heat set. Heat setting can cause the hose clamps
to loosen. Loose hose clamps can cause leaks. There have been reports of component failures that have
been caused by hose clamps that have loosened. The constant torque hose clamp will help prevent these
failures.
The constant torque hose clamp is installed
correctly under the following conditions:
• Screw tip (1) extends 6.35 mm (0.25 in) (A)
beyond the housing.
• The Belleville springs are closed almost flat
after the screw (2) is tightened to a torque of
11 Nm (8.1 lbf ft).
Fig. 29
1.2.2 Fastener tightening specifications
Assembly torque for metric fasteners
Standard
High
Low
Thread size
Torque lbf ft
Torque Nm
Torque lbf ft
Torque Nm
Torque lbf ft
Torque Nm
M6 x 1
8 to 10
9 to 15
9 to 11
10 to 16
3.5 to 4.5
5 to 7
M8 x 1.25
19 to 23
21 to 35
20 to 24
23 to 37
10 to 12
12 to 18
M10 x 1.5
37 to 45
45 to 65
40 to 48
48 to 72
20 to 24
23 to 37
M12 x 1.75
67 to 83
80 to 120
72 to 88
85 to 125
31 to 39
40 to 60
M14 x 2
108 to 132
130 to 190
120 to 140
145 to 205
55 to 65
65 to 95
M16 x 2
160 to 190
200 to 280
180 to 220
230 to 310
80 to 100
105 to 145
M20 x 2.5
305 to 375
400 to 520
350 to 430
460 to 600
165 to 205
210 to 290
1. General
1-18
New Leader® L4258G4/L4330G4
79035617A
