Taboos in construction machinery maintenance—Using emery cloth to polish bearing bushes and tightening bolts too tight

Maintenance taboo 6: Use emery cloth to polish the bearing bush
For some inexperienced repairmen, scraping is a difficult job. Since the scraping technique is difficult to master, it is difficult for the bearings to meet the technical requirements. For this reason, when some people replace the bearing bush, in order to increase the contact area between the bearing bush and the crankshaft, they use emery cloth to polish it instead of scraping the bush.
This method is extremely undesirable in actual maintenance, because the abrasive grains on the emery cloth are relatively hard, while the bearing alloy is soft. In this way, the sand grains are easily embedded in the alloy during grinding, and the wear of the journal will be accelerated when the diesel engine is working. Shorten the service life of the crankshaft.

Maintenance taboo 7: Bolts are tightened too much
During the disassembly and assembly process of engineering machinery, bolts in many parts have specified torque requirements, such as transmission boxes, cylinder heads, wheel hubs, connecting rods and front axles. The tightening torques are specifically specified in the instructions. Do not Feel free to change it. However, many users mistakenly believe that tightening it will be safer, but tightening it too tight will cause the screws or bolts to break, and may also cause failure due to thread slippage.

There are many taboos in construction machinery maintenance. This is the third article in this series. We will continue to update it. If you are interested in it, you can pay attention to us. In addition, if you need to buy used excavators, used loaders, used graders and other used machinery or related accessories, you can contact us at any time.