This part is commonly Used on models:
108-1370 Gearbox Replacement Kit, 1989 and After Mowers for Groundsmaster 200/300 Series
30366 60in Side Discharge Mower, Groundsmaster 3320/3280-D Traction Unit
31335 72in Guardian Recycler Mower, Groundsmaster 3280-D Traction Unit
30404 Base 72in Mower, Groundsmaster 3320/3280-D Traction Unit