Abstract: Statistically analyzed here in the paper are the running faults of the gear reducer of the Φ177 mm pipe mill as occurred over the recent years.Identified are the major elements restraining the long-life running of the reducer.i.e., poor loading ability of the bearing, serious vibration of the link rod due to its improper structure, and insufficient lubrication of the bearing.Accordingly corrective actions are determined, including redesigning the model of the bearing to increase its loading force, enlarging the caliber of the oil-supply pipe to ensure adequate lubrication, redesigning the bearing gap adjusting bush to ensure its hardness up to relevant requirement, optimizing the adjusting values of the bearing clearance and the gear side clearance, and modifying the structure of the long link rod to reduce its vibration.