In the TC Tronic, the torque converter clutch permits an input torque of up to 2,700 Nm. During travel, the driver can either engage gears manually with just a finger tip – clutch operation is automatic – or rely on the drive program. In the manual mode, an electronic check prevents incorrect gearshifts. The integrated primary retarder ensures wear-free braking until the vehicle stands almost completely still.
The TC Tronic HD (Heavy Duty) was developed for applications in crane trucks and heavy trucks with a weight of 72 tons and more and has been designed for torques of up to 3500 newton meters. For the TC Tronic HD, ZF engineers have combined the AS Tronic with a further developed torque converter clutch: the TC HD (Heavy Duty). Unlike the TC Tronic, this transmission is not equipped with a primary retarder but with a speed-dependent secondary retarder, the ZF-Intarder. The intarder is particularly suited for brake operations at speeds higher than 25 km/h. Another distinct feature of the TC Tronic HD is the possibility of maneuvering in open converter operation.
A hydraulic pump and oil cooler help keep oil temperatures below 130°C most of the time. Moreover, the HD variant does not require an additional external oil tank. As the primary retarder has become obsolete, it was possible to integrate the oil supply required for the hydrodynamic torque converter into the housing.
Upon request, this tank can be filled with 26.5 liters of the Ecofluid M oil which has also been developed by ZF. On the one hand, this makes the final oil fill easier, and on the other hand, the Ecofluid M features higher mileages and longer oil change intervals ch, in turn, leads to improved economy in service.
