Wear on opposing areas of the separation planes
DESCRIPTION OF THE DAMAGE
- Significant wear marks in the area of the diagonally opposite reliefs
- Crown of the bearing shell significantly less worn
- In severe cases: signs of material fatigue and initial rubbing marks visible
Pronounced wear is visible in the relief, whilst the bearing crown is considerably less worn.
DAMAGE ASSESSMENT
If the bearing shells in this area carry weight, the fault is severe. Misalignment of the bearing shells to one another due to aninstallation error can be the cause for the wear that occurs. The bearing clearance is too low locally due to the cover offset, meaning that the lubricating film is not fully stable and mixed friction occurs in places. If the shortage of lubrication continues, the temperature increases due to the frictional heat that results. The shortage of lubrication continues to intensify due to the increasing temperature level and the process reinforces itself until the first initial rubbing marks occur and fatigue damage occurs due to increased surface pressure.
POSSIBLE CAUSES FOR THE DAMAGE
- Wrong bearing cap installed
- Bearing cap installed twisted by 180 degrees
- Unsuitable tool or wrong locating bolts used
- Wrong tightening sequence or wrong tightening torque of the bolts
Remedy
The bearing must be replaced and the cause rectified as the bearing is not designed to carry weight in this area:
- Pay attention to the relation of the bearing shells to the cylinder
- Only mount suitable bolts with an appropriate tool
- Tighten bolts in accordance with the manufacturer‘s specifications with regard to tightening torques and the tightening sequence
- Check bore: dimensions, roundness, cylindricity, surface must be within certain specified tolerances