In this video is a followup of my older video about the Lego 7740 where I improved its speed by updating hardware. The train makes some sort of irritating squeaking noise, which worsened after improving the speed.
In this video I try to fix the noise problem by opening the motor and lubricating the parts. The results are great! not only did the noise disappear but the speed improved at the same time.

Other video's about opening and repairing 12V Lego motors:
   • Repair of a Lego 12v red train motor  
   • Repairing a black 12v train motor