For optimum performance on the Model AT48,
AT60, AT72, the gearbox oil level should be
checked every month or 500 hours of operation.
To check the oil level, remove one of the upper oil
level plugs to verify the gearbox has a sufficient
level of oil. The oil should be drained and refilled
every six (6) months or 2500 hours with Mobil
600W Super Cylinder oil.
NOTE: Make sure to check the oil level on both
the primary and secondary gearboxes.