other analogous driver selectable input device the control assembly 50 may include various electronic computation logic and output devices as well as devices which receive signals and provide logic decisions based upon feedback or signals provided by components of the transfer case assembly 16 the foregoing and following description relates to a vehicle wherein the rear drive line 20 functions as the primary drive line i e it is engaged and operates substantially all the time and correspondingly the front drive line 30 functions as the secondary drive line i e it is engaged and operates only part time or in a secondary or supplemental fashion such a vehicle commonly being referred to as a rear wheel drive vehicle these designations u201c primary u201d and u201c secondary u201d are utilized herein rather than u201c front u201d and u201c rear u201d inasmuch as the invention herein disclosed and claimed may be readily utilized in transmissions and transfer cases wherein the primary drive line 20 is disposed at the front of the vehicle and the secondary drive line 30 is disposed at the rear of the vehicle such designations primary and secondary thus broadly and properly characterizing the function of the individual drive lines rather than their specific locations referring now to fig1 and 2 the transfer case assembly 16 incorporating to the present invention includes a multiple piece housing assembly 60 having a plurality of planar sealing surfaces openings for shafts and bearings and various recesses shoulders counterbores and the like to receive various components or assemblies of the transfer case assembly 16 an input shaft 62 includes female or internal splines or gear teeth 64 or other suitable coupling structures which drivingly couple the output of the transmission 14 illustrated in fig1.