915 DIFFERENTIAL IDENTIFICATION

915 for 8:31 ring and pinion

915 for 7:31 ring and pinion

The 915 gearbox uses two different differentials: one for the 7:31 ring and pinion and another for the 8:31 ring and pinion. In the pictures above one can see that the diff using the 8:31 has a groove around the edge of the ring-gear flange; the diff using the 7:31 does not have this groove.