A cab suspension for a vehicle having a chassis supporting a cab with the cab being supported on the chassis at a forward location and at a rearward location so as to permit vertical movement of the rearward end of the cab relative to the chassis. Conventional forward support structures connect the forward end of the cab to the chassis. A rearward support structure or suspension unit connects the cab to the chassis at the rearward end of the cab to provide relative vertical movement therebetween. The structure comprises an elongated metal tube having its longitudinal axis disposed transversely with respect to the longitudinal axis of the chassis with the tube being secured to the chassis. The tube has an elongated, resilient rubber or elastomeric cartridge positioned therein which has an elongated torsion bar extending therethrough which is in engagement therewith so that the cartridge restricts rotational movement of the torsion bar with respect to the tube. Lever arms are fixedly secured to the ends of the torsion bar and extend forwardly therefrom for adjustable connection to a bracket which is secured to the lower rearward end of the vehicle cab.