Abstract: A spring mounted tracked tractor chassis comprises a double-armed balance beam, having upper and lower arms, rotatably mounted by the lower arm to a main arm. The balance beam carries a journal of a tensioning wheel and its upper arm is rotatably connected with a tension jack arranged on the main arm. Running wheels of the chassis are secured on the main arm through rockers with primary springs inserted therebetween. A secondary spring is mounted between the main arm and a console located on the tractor body. A drive wheel rotational axis is positioned below and behind the rotational axis of a countershaft of a portal gear. The rotational axis of the countershaft is positioned below and behind the rotational axis of a ring gear of a bevel gear.