Crankshaft assembly,  M110

Checking, replacing and tightening conrod bolts

 

 
03—310 Checking, replacing and tightening conrod bolts

 
Conrod bolt sizes

 
Version
Part Number
Distanc a and b (fig., po a
e
int 1) b
Thread dia. d
Expansion stem dia. c when new (fig., point 1)
Min. Expansion stem dia.
1st version
110 038 01 71
5.5
3
M 10×1
8.4-0.1
8.0
2nd version
110 038 03 71
4.5
3rd version
110 038 04 71
6.6

 
Conrod bolt installation pressure
45000 N

 
Conrod nut torque

 
Initial torque
40-50
Torque angle
90-100°
Self-made tool

 
Steel plate
see fig., point 3

 
Checking
m110 - 0081-1.jpg
1 Measure smallest expansion stem diameter before reusing.

 
03.2-310/1 F3

 

 

 

 
Note: If the minimum expansion stem diameter reaches or is less than 8.0 mm, replace conrod bolt.
Only knock out a conrod bolt to replace it. Use third version conrod bolts for repairs.
m110 - 0082-1.jpg

 
Replacing
m110 - 0082-2.jpg
2   Knock out conrod bolts.
3   Press new bolts into conrod with a pressure of about 45000 N, or knock in with a hammer and mandrel.
Place the connecting rod on a ground steel plate when knocking in or pressing in conrod bolts.
Distance between holes a = 64.6 mm Bore b = 11 mm

 
Tightening

 
4   Lubricate nuts and threads.
5   Tighten conrod nuts to a torque pressure of 40-50 Nm and a torque angle of 90-100°.
Attention!
Tighten conrod bolts knocked in with a hammer to a torque pressure of 60—70 Nm and a torque angle of 90-100° for the first time.
m110 - 0082-3.jpg

 
03.2-310/2 F3

 

 

 
Make sure that this instruction is observed, since otherwise the nuts of the conrod bolts may become loose.
Note: If no angle of rotation wrench is available, the connecting rod nuts can also be tightened by means of a normal socket wrench with toggle in one step by an angle of 90—100°. Estimate angle as accurately as possible. To eliminate angle faults, do not use a torque wrench for tightening according to angles of rotation.

 
03.2-310/3 F3