In these days, diagnostics techniques enabling the condition based maintenance are being paid great attention in many industry fields in order to achieve increased reliability of the system as well as the reduction of operating cost. The techniques are particularly useful to the system that costs a tremendous amount for the maintenance or leads to the catastrophic results when failure occurs. Among these systems, the gearbox is expensive to maintain and replace when failure occurs. There are two types of gear fault. One is the spall and the other is the crack. Cracks are more critical in the sense that it grows suddenly to the tooth breakage. Fault classification of spall and crack is conducted based on the transmission error (TE) and vibration signals. In this study, Ensemble Empirical Mode Decomposition(EEMD) is conducted to classify spall and crack faults from normal signals in TE. As a result, spall and crack are not classified in vibration signals but in transmission error.