In the same way as the lighter 424/427 series, the 437.1 series replaced the preceding 425 and 435 series from 1988. The external appearance remained unchanged, the technology was modernised and the OM engine series was introduced. With the 437.1 series the Unimog entered new output classes and exceeded the 200 hp mark for the first time. The model series had 28 model variants, making it the most extensive Unimog series to date. Apart from traction head variants there were heavy-duty implement carriers and, for the first time as standard, a 3-axle chassis. The 437.1 series remained in production until 2003 with a total of 10,718 units. The 437.1 series also served as the basis for the 436 series produced under licence in Turkey. It also provided the base chassis for special-purpose vehicles by other manufacturers, e.g. the KMW Dingo 1.