The present invention concern a method to convert the rear assembly of a light vehicle (1 ), the existing chassis construction is modified through the use of a subframe (20) intended to be joined to a chassis construction, the subframe includes two longitudinal frame beams (22) and a transverse frame beam (24), the method including the steps of: - removing the existing rear suspension, - attaching a subframe (10), - mounting separate rear suspensions (14) one on each side of the vehicle, each suspension having a support arm (27) and spring components (30,31), - assigning the rear assembly a box-like construction (15) intended to form a lowered portion of floor (10). An extensive inner space is achieved by the steps: - assigning to the transverse frame beam (24) at each end a beam construction (60) terminating at a backwardly facing end section (62) in which a first active part of a joint (29) is arranged, - assigning the forward end (28) of the support arm (27) a second active part of the said joint (29), - arranging the support arm (27) such that it can pivot at the end part (62), - arranging the spring components (30, 31 ) between the rear end (34) of the support arm (27) and the longitudinal frame beam (22), and - arranging the said support arms (27), the longitudinal frame beams (22) and the spring components (30, 31) at the side of the longitudinal side walls (17) of the box-like lowered portion of floor.
