Slipping truck connection

[cantonkid]

I have two locos that the motor is in the middle, it has a small arm on both sides connecting to the trucks with a small cup that is pressed onto the gear shaft that turn the wheels. The cup is slipping on the shaft so the rear wheels are not turning. How do I fix this?

[dutchbuilder]

The arm is called a drive shaft.
Try a little bit of super glue after cleaning the shaft.

Ton