page_title: Sisu K-44
section_title: Tandem axle
hierarchical_section_title: Sisu K-44 / Technical Data / Transmission / Tandem axle
caption_attribution_description: English: Sisu bogie system from the time before the Vanaja type lift bogie was taken to use.
context_page_description: Sisu K-44 is a three-axle 4×4+2 driven lorry made by the Finnish heavy vehicle manufacturer Suomen Autoteollisuus from 1959 to 1965. The most usual applications were for log transportation and earth moving vehicles. The K-44 was noted for its excellent gradient capabilities. The legally permissible maximum vehicle payload was between 7 800 and 11 750 kg: with a trailer this increased to 20 000 kg. The K-44s were powered by Leyland diesel engines with power outputs of between 85.8 and 156.7 kW.
  The K-44 was replaced in 1965 by the K-145.
context_section_description: The foremost axle on the tandem axle is powered. When fully loaded, the K-44 carries approximately 62% of the weight lying on the tandem axle. The rear, non-driven axle, is linked to the driven axle through a simple sub-assembly consisting of 3.5 in (88.9 mm) wide and 1,500 mm (59.1 in) long leaf springs and rocker arms. When the torque delivered to the rear axle is increased, the mechanism automatically shifts vehicle weight away from the non-driven axle to the driven axle, improving traction when most needed. Additionally, more of the weight can be moved to the driven axle manually using an electro hydraulic system. In order to reduce fuel consumption and tyre wear the non-driven rear axle can also be raised completely off the road/surface, if a third load-bearing axle is not needed because the vehicle is running empty: running on just two axles also reduces the K-44's turning circle.
  The wheel size is 7.5–20" and each wheel is held in place with ten nuts. Both axles on the bogie are fitted with double wheels as standard other than on the K-44ST, which made do with single wheels on the non-driven rearmost axle.
  The normal wheelbase of the tandem is 1,150 mm (45.3 in): alternative bogie wheelbases of 1,200 mm (47.2 in) and 1,270 mm (50.0 in) also appear on the manufacturer's data sheets.
  On the early K-44s the tandem's driven axles are identical on the middle-weight "Kontio" and the heavy-weight "Jyry" versions. The axle, designated "Type ATK" was designed by SAT and was based on the manufacturer's "Type ATD" axle originally introduced for earlier models n the early 1950s. The "Type ATK" proved durable in the Kontios, but was unable to cope with the greater power and load of the Jyry trucks, and in the early 1960s SAT developed a more robust driven axle, known as the axle "Type BTK", for the heavier variants.
  The axle housing is a welded construction made from formed steel. The transaxle used hypoid gears.
caption: Tandem axle of Sisu K-44.
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