THE SITUATION
A 70:1 Primary Bank Lothian worm reduction gearbox was brought in for refurbishment after showing clear signs of wear across several critical components. Inspection revealed heavily scored bronze liner bushes, impact damage to the output shaft, fretting on the crank arm seal journal, and deterioration on both the worm and worm wheel running surfaces. Left unaddressed, these issues had the potential to impact performance, reliability and long-term service life.
THE SOLUTION
The gearbox was fully stripped, inspected and refurbished by our engineering team to restore its performance and reliability.
The overhaul included machining the bronze liner bushes to an oversize bore and manufacturing a new EN8 output shaft to suit the revised dimensions. The crank arm seal journal was reclaimed using a precision sleeve repair, while new bearings, seals and lubrication components were installed throughout the unit. Damaged pipework was also repaired, and the worm and worm wheel were carefully inspected, dressed and assessed before the gearbox was rebuilt.
Following reassembly, the gearbox underwent testing and final inspection to ensure it was ready for reliable operation.
THE RESULT
By combining precision machining with targeted component replacement and repair, the gearbox was successfully restored to service-ready condition. Rather than replacing the complete unit, the refurbishment extended the operational life of the gearbox, improved reliability and provided the customer with a cost-effective solution that minimised downtime and maximised asset value.
