MTU Detroit Diesel 183 Series Technical Publication page 188

Group 03
Subgroup 7004
Page 8
Note
It is often difficult to differentiate between the nickel barrier and softer running surface. If in doubt, consult a bearing
specialist.
20080/1 E 98-12
Check parallelity of conrod bores.
Measure permissible parallelity deviation (B) between
conrod bearing and conrod bush bore to measuring
distance (C).
Measure distance (A) from centre conrod bearing bore
to centre conrod bush bore.
For required measurements and limit values, refer to
the Tolerance and Wear Limits List.
If limit values are exceeded, replace conrod.
Note
The conrod is not to be straightened!
Checking and assessing conrod bearing shells
Check bearing shells' surface condition and for signs of
wear; replace worn or chipped shells.
Replace bearing shells as part of every W6 overhaul,
see Group/Subgroup 03-6312.
The bearing shells have the following material structure:
1 Running surface (from 12 µm to 20 µm)
2 Intermediate layer (nickel barrier)
3 Bearing metal
4 Steel support shell
An important factor for assessing extent of bearing shell
wear is the shape and extent of exposed nickel barrier
areas.
Use of bearing shell is reduced to 70% of running
surface in friction area!
Task Description