Auto Lube reduces contamination and wear of pin bushing, extend machine life and help avoid downtime.

Proper lubrication reduces excessive contamination and wear of bronze pin/bushings. Which helps to maximise the profitability of capital equipment, ensures up-time and decreases the frequency of downtime due to costly repairs.

Today’s construction and mining equipment use the most sophisticated form of bronze pin bushings. Their ability to reduce wear is impressive, nevertheless, a problem lies within the nature of the material itself – bronze. Bronze is extremely reliable and very durable when used as a ‘wear’ material but it is not contamination-proof. The purpose of wear materials is to reduce damage to structural steel components. The bronze bushing is much cheaper to replace than something like a wheel loader boom arm.


The effect of contamination on pin bushings is directly related to scaring, skidding/ploughing and smearing. When excessive contamination builds up between a pin and bushing surface, the rotation of the pin and the pressure load starts digging contamination into the bronze bushing. When contamination keeps building up, it will restrict the movement of the pin by increasing friction.

Open lube points that lack fresh grease allow dirt to easily enter the system.
Open lube points that lack fresh grease allow dirt to easily enter the system.

Due to increasing friction and the load pressure, the pin will eventually gouge the bronze and start removing material from the bushing to allow the pin to rotate. These material deposits lead to additional contamination between the pin and bushing, making the problem even worse. If this process continues, the space between the pin and bushing will increase, leading to even more contamination and wear. When all the bronze bushing material is worn away, the pin will start digging into the steel structure of the equipment.

Wear evolution due to contamination:

  1. Good bushing
  2. Worn bushing
  3. Worn bushing affecting the frame

Under these conditions production machinery is generally put out of service and the bushings may need to be replaced.

  • If only the bushing is damaged, the pin and bushing set may need to be replaced.
  • If the pin has damaged the structural steel of the equipment, a ‘line bore’ will probably be required, increasing the cost of the repairs exponentially.

Cost of bushing pin repairs

For small machines, a conservative cost for replacing the damaged pin / bushing, could be between R6 000 to R30 000 and is relatively time-consuming, as the equipment may need to be transported to an off-site workshop. The duration of a “simple” removal and replacement of work parts lasts between 5-8 hours if the pin / bushing is not very stuck. Furthermore, when a work pin has damaged the structural steel of the equipment, operators are faced not only with the costs for replacing the damaged pin / bushing, but also with additional downtime and repair costs for line boring (R10 000 per hole), welding, and refitting.

The importance of proper lubrication maintenance

Proper lubrication can significantly help to reduce the need for replacement or repair of pin bushings. Most pin bushings today have ‘grease grooves’ on the inner diameter where applied lubricants form a film thickness for the pin to rotate on. The application of lubricants into these grooves also aid in “purging” contaminants from the bushing by forcing out unwanted materials, however, if proper greasing intervals are not maintained the groves become a house for contamination. Without proper and consistent lubrication, wear can occur because the bushings are not “purged” and cleaned frequently.

Automatic lubrication minimises damage and costs

Automatic lubrication systems consistently dispense accurate doses of lubricant. It enables the permanent purging of contamination from the pin and bushing while the system is working. By greasing during equipment operation, the entire pin is coated and equal purging of the pin’s circumference is obtained. This increases equipment life and extends machine performance, while reducing the maintenance- and repair frequency which leads to minimal downtime.


FloSolve’s team of experts are available to assist you with a selection of automatic lubrication solutions for your business.
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All this information in one overview?

Article sourced from Graco Heavy Equipment Solutions