Volvo SD75B Vibration Will Not Engage
Fault Codes & Symptoms
Vibration system inoperative Related symptoms: - Grinding noise from drum - Metal debris in drum bearing oil The operator reports that the machine will not start vibrating when commanded. All other machine functions are normal.
Confirmed cause: One of the main eccentric shaft support bearings had failed and seized, preventing the shaft from rotating. Repair performed: Drained the drum bearing housing. Removed the end cover of the drum. Removed the failed bearing, race, and cage fragments. Inspected the eccentric shaft and bearing housing for collateral damage. Installed a new bearing and seals. Refilled the bearing housing with the specified lubricant. Verification: After reassembly, the vibration system was tested. It engaged immediately when commanded and operated smoothly at both low and high amplitude settings. Technician notes: - The seized bearing was on the opposite side of the drum from the drive motor. - Checking for metal debris during the initial drum lubricant drain could have been a useful shortcut. - This failure is difficult to distinguish from a hydraulic motor failure without checking pressures first.