a backbone frame. All other parts of the truck are mounted to this rigid assembly. The inherently high torsional and flexural rigidity of this layout protects superstructures from the motions and forces on the axles. Torque distribution to the axles is also carried within the backbone. Differential Tatra differentials are a unique design that uses two opposing spiral bevel gears instead of the usual single set. The differential gears are part of the input drive shaft rather than between the output axles as in a conventional differential. All versions of the Tatra differential have locking pins that can force the differential gears to rotate together, "locking" the differential. This arrangement had two distinct advantages. The first is that the dual output bevel gears allow the axles to swing around the drive axle without the need for universal couplings. The second is that the input drive shaft goes essentially straight through the differential housing, allowing simple coupling to a second set of swing axles. This modular design enables configurations of 2, 3, 4, 5, or even 6 axles with all axles driven. The whole assembly is part of the backbone frame. Suspension Front Mechanical suspension of load capacity up to 8 tons per axle by torsion bars – for versions with one steered front axle (4x4 and 6x6) or by leaf springs – for versions with two steered axles (6x6, 8x8, 10x10 or 12x12). Air-bellows, with a load capacity of 9 tons per axle and a possibility of a ground clearance regulation. Rear Mechanical – by leaf springs, with a load capacity of up to 11.5 tons per axle Air-bellows with a load capacity of 10 tons per axle and a possibility of a ground clearance regulation Tatra King Frame suspension system - combination of an air-bellow with a coil spring placed inside, with a load capacity of up to 11.5 tons per axle or combination of air-bellows with leaf springs, with a load capacity of 13, 15 and 16.5 tons per axle. All suspension types are equipped with telescopic shock absorbers; some versions also have stabilizer torsion bars. Engine The Tatra engine is an air-cooled, OHV, currently 12.7 litre 90° V8 120 x 140 mm diesel engine with direct fuel injection. It is turbocharged by one Holset WasteGate turbocharger, and equipped with an intercooler placed directly over the engine. The engine is equipped with a mechanically controlled in-line Bosch injection