This paper describes a tool for analyzing tooth contact and motion transmission errors of spiral bevel and hypoid gear sets in the loaded state. Basic tooth geometry and no-load contact is described by standard tooth contact analysis programs (TCA) and blank dimensions. Relative deflections of the gear and pinion, due to load, are introduced either from deflection test data or are assumed based on typical deflections for an axle with similiar geometry. Loading is assumed to be Hertzian taking into account boundary limits. Tooth deflections are based on beam theory. Load sharing is achieved through an iterative technique considering surface mismatches, tooth deformation and tooth bending. Some preliminary results are included. Experimental verification is needed.