My sp-15 started squealing today; I deduced the noise was coming from either the motor or the ink drum assembly – inspected the motor oil reservoir and topped it up without overfilling. Moved onto the ink drum assembly x 20613 and on removal found the ink drum shaft to be very resistant to rotation. I’ve loosened and removed the 2 x-19665 ink drum bearings; the ink drum gear and shaft and cleaned all components of the assembly. All components, including the phenolic lining of the drum appear to be in reasonable condition. One possible explanation for the squeal is that the ink drum shaft could not freely rotate due to a build up of grime; another might be that one of the ink drum bearings had shifted and was tight against the phenolic liner. On re-assembly the ink drum shaft rotates freely. My question for you all: which lubricant would you recommend for the ink drum shaft?
Hope all is well with you and yours
Looking forward to your advice