The Renk RK 304 is a hydromechanical power shift, reversing and steering transmission and is used in new power packs installed in upgraded M48, M60 and Centurion tanks, the Otobreda Palmaria 155 mm self-propelled howitzer (coupled to MTU diesel) and prototypes of the Arjun Indian MBT.

The Renk 304 transmission can be attached to the engine directly or via an intermediate structure. The service and parking brakes are arranged on the two transmission output shafts positioned transversely to the input drive.

The connection to the final drives can be made via disconnectable gear-type couplings or via universal joints. Two mounting points are arranged on the transmission for a three-point support of the power pack.

The two-radii superimposed steering transmission is infinitely variable in the large radius range.

Dry running disc brakes at both output shafts act as service and parking brakes respectively. Static braking torque per side is 12,000 Nm. The electrically operated retarder at the transmission input side is electrically actuated with a continuous brake power of 225 kW. The power take-off is primary side driven, connectable, with a maximum output of 110 kW.

Renk RK 304 transmission with two fan drives on top, infinitely speed controlled. This transmission is suitable for front or rear drive and allows the vehicle to be tow started.

Options for the RK 304 transmission include connecting cable between gear selector, electronic control unit, transmission and vehicle, output gear-type couplings, final drives, sprocket drums, brake actuating system and an external testing device. The version for the Indian Arjun MBT is designated the RK 304-I.

Production. By mid-1999 over 1,500 of these transmissions had been completed. As far as it is known, all applications of the Renk 304 transmission have been in export applications.