Please check at regular intervals if the rollers on the carriages are still running properly. If this is not the case, they must be replaced immediately. Please make sure that the rollers are well tightened after replacement. It is also important to ensure that the carriage has as little clearance as possible to the central guide tube. 

Open outer rollers to detach the carriage from the central guide tube.

Make sure that the rollers are fastened tight. Allow as little play as possible when adjusting the roller.

Check every three months and with any service if the rollers still move!!! Use WD-40 with every service.

Allow as little play as possible when adjusting the roller.