Planetary gearboxes require regular inspection and cleaning to remove dust and debris, as well as checks for cracks or oil leaks. Proper lubrication maintenance is essential, including timely replacement with the correct lubricant, checking fasteners, monitoring operating temperatures, and avoiding overload. Installation must ensure balanced alignment; severe impacts should be avoided, and measures taken to prevent moisture and rust. Professional maintenance should be performed regularly. If abnormal oil temperature rises or unusual noise occurs during operation, the unit must be stopped to investigate the cause and rectify the fault before resuming use. Oil changes should be performed at operating temperature, with old oil drained completely; units stored for more than one year require rust-prevention treatment.
When servicing the planetary gear transmission mechanism of an automatic transmission, the clutch piston stroke must be measured. The tooth surfaces of the sun gear, planetary gears, and ring gear must be inspected; components showing wear or fatigue spalling should be replaced. The clearance between the planetary gears and the planet carrier must be checked; the standard clearance is 0.2–0.6 mm, with a maximum limit of 1.0 mm. The locking direction of the one-way clutch must be verified, and components should be replaced if rollers are damaged or if the inner/outer race raceways show wear.
Compared to fixed-axis gearboxes, planetary gearboxes feature more complex structures and modes of motion. During operation, planetary gears simultaneously revolve around the center of the gear train and rotate about their own axes; the simultaneous meshing of multiple gear pairs results in more complex vibration responses.
