The invention relates to a method for the assembly of a balance shaft unit for use in motor vehicles. The assembly includes a housing having a bearing section, a rotating component and at least one rolling element bearing for the axially fixed journaling of the rotating component in the bearing section of the housing. The rolling element bearing has a first ring section associated with the rotating component and a second ring section associated with the bearing section. First, the rolling element bearing is axially fixedly installed on the rotating component or in the bearing section. Next, the rotating component is cooled and/or the housing part is heated. Finally, the rotating component is introduced into the bearing section and is held until a temperature compensation has taken place between the rotating component and the housing such that a shrink-fit connection is established.