The axles used in early Sisu models were produced by Timken. Later the axle housings were locally produced. In 1942 SAT started its own axle production; the first models were based on Timken products and produced in Helsinki. Kirkstall axles were later used in some applications. Soon after Vanajan Autotehdas was merged into SAT in 1968, the outstanding lifting tandem system, used previously in Vanaja lorries, was adopted to Sisu; the robust structure was most welcome because the SAT's own corresponding solution was suffering of fractures. Axle production was moved to Hämeenlinna in 1985 and axle production was split off as a separate company, Sisu Axles, and finally sold to investors in 1999. During the Renault partnership also Renault axles were in selection.