Legolova

Hi, I recently pulled out my childhood trainset (7720) for the first time in 20 years, set it up and...awesome, it goes but its really noisy, I took the motor out of it's housing and tested it. I found that the motor itself was causing the noise (a loud squealing/squeaking). Can I fix it or do I need to replace it? It still seems to run ok, just noisy.