Weichai America Corp.
Revision: October 2018 26
Torque Head Bolts and Nuts
NOTE: Cylinder head bolts are allowed to be reused and torqued only three (3)
times. Discard these bolts after the third torque because they lose their elasticity and
strength and should not be torqued for a fourth time. Remove cylinder head covers.
Illustration 14: Tighten order of cylinder head bolts and nuts
Tightening Process is as follows:
A. Align the cylinder head with the cylinder block. Apply a proper amount of clean
lubricating oil to the threads and pressure-bearing surfaces of shoulders of the main bolts
of cylinder head and the shouldered nuts. Install the main bolts to the cylinder head.
Install the clamping blocks and nuts to the auxiliary bolts of cylinder head.
B. Tighten the main bolts and nuts of auxiliary bolts of cylinder head to the torque of (30~50)
Nm.
C. Tap the clamping blocks so that they fall in place.
D. Tighten the nuts of auxiliary bolts in the specified sequence to the torque of 100N·m.
E. Tighten the main bolts in the specified sequence to the torque of 200N·m.
F. Tighten the nuts of auxiliary bolts in the specified sequence by 90º. Then make marks on
the nuts.
G. Tighten the main bolts in the specified sequence by 90º. Then make marks on the bolts.
H. Tighten the nuts of auxiliary bolts in the specified sequence by another 90º to the torque
of (120~160) Nm.
I. Tighten the main bolts in the specified sequence by another 90º to the torque of
(240~340) Nm.
J. The cylinder head bolts and nuts shall be tightened according to the order given by
Illustration 14, in which, those numbering 1-21 are nuts of auxiliary bolt, while those
numbering 22-45 are main bolts of cylinder head.
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com