A peculiarity of all-wheel drive off-highway vehicles is that their running abilities (cross-country mobility, tractive and velocity properties, turnability and the like) depend not only on total traction effort but also on its distribution between driving wheels. The latter is in great measure determined by actuating vehicle system and characteristics of the mechanisms installed in power dividing transmission units, i.e. in interwheel, interaxle reduction gears, and transfer cases. The characteristics of locking performance of these mechanisms regulate the circumferential force distribution between driving wheels and, respectively, a vehicle's performance indicators.Such mechanisms have been created and are being created in a multitude. The classification of power dividing mechanisms and system is given. They provide a high level of the traction performance of all-wheel drive off-highway vehicles and agricultural tractors, in particular.The article features a statistical analysis of all-wheel-drive agricultural tractors and their differentials with data on more than 4000 tractor models produced since 1970.It is shown that limited slip differentials with 6 various characteristics developed on the basis of various constructional elements enjoy a wide spread.Limited slip differentials with various characteristics must be used in different transmission units in order to provide maximum efficiency of tractors. Lack of unification among those differentials impedes employment of such mechanisms with various characteristics on one and the same tractor. This problem is solved in the article: unified limited slip differential systems have been developed, in which various interaction of differential's primary constructional elements provides different characteristics. This has been implemented not only for the mentioned differentials with 6 various characteristics. Using those, one more differential (the seventh) has been designed. The description of the developed differentials and the differentials' locking performance is included.