Yanmar 3YM30, Service Manual

Page: 229 / 231

14. Tightening torque for bolts and nuts
208
14. Tightening torque for bolts and nuts
14.1 Main bolt and nut
14.2 Standard bolts and nuts (without lube oil)
No Name
Thread diameter
x pitch
Lube oil application
(thread portion and seat
surface)
Torque
N•m(kgf•m)
1 Head bolt M9 x 1.25 Coat with lube oil 53.9-57.9 (5.5-5.9)
2 Rod bolt M7 x 1.0 Coat with lube oil 22.6-27.5 (2.3-2.8)
3 Flywheel retainer bolt M10 x 1.25 Coat with lube oil 80.4-86.4 (8.2-8.8)
4 Metal cap retainer bolt M10 x 1.25 Coat with lube oil 75.5-81.5 (7.7-8.3)
5
Crankshaft pulley bolt
(FC250 pulley)
M10 x 1.25 Coat with lube oil 83.3-93.3 (8.5-9.5)
6 Fuel pump gear nut M12 x 1.75 Coat with lube oil 58.8-68.8 (6.0-7.0)
7 Nozzle fastening nut M20 x 1.5 No lube oil 49-53 (5.0-5.4)
8
Fuel injection pipe
joint nut
M12 x 1.25 No lube oil 29.4-34.4 (3.0-3.5)
9 Glow plug M10 x 1.25 No lube oil 14.7-19.6(1.5-2.0)
10
Governor weight
support fastening nut
M12 x 1.25 Coat with lube oil 68.7-73.7(7.0-7.5)
N•m (kgf•m)
Name Screw dia. x pitch Tightening torque Remarks
Hexagon bolt (7T) and
nut M6 x 1 9.8-11.8(1.0-1.2) Use 80% of the value at
left when the tightening
part is aluminum.
Use 60% of the value at
left for 4T bolts and lock
nuts.
M8 x 1.25 22.5-28.5(2.3-2.9)
M10 x 1.5 44-54(4.5-5.5)
M12 x 1.75 78.2-98.2(8.0-10.0)
PT plug 1/8 9.8 (1.0) -
1/4 19.6 (2.0)
3/8 29.4 (3.0)
1/2 58.8 (6.0)
Pipe joint bolt M8 12.7-16.7(1.3-1.7) -
M10 19.5-25.5 (2.0-2.6)
M12 24.4-34.4 (2.5-3.5)
M14 39.1-49.1 (4.0-5.0)
M16 48.9-58.9 (5.0-6.0)