.

Bolinder-Munktell BM 470, BM 471(Bison) / BM-Volvo 470, 471

The diesel engines of the first series were upgraded for the BM 350 and BM 470. The engines were now designated 1 113 and 1 114. The output of the larger BM 470 was a remarkable 73 hk. The Bison, as the tractor was called, was also launched as “one of the most powerful tractors in the world”. This engine power was put to good use too, in heavy haulage with dumper trailers. The gearbox had five forward speeds and one reverse. In Sweden the Bison came with a safety frame approved by the Swedish National Board for Occupational Safety and Health, with an option to add a cab. A complete truck-type cab with space for two passengers was available. The total weight was 3 360 kg without safety frame and the wheelbase was 2 175 mm. The brakes were mechanical, fully-enclosed steering brakes which could be coupled together for braking on both wheels. When lots of power was needed on large farms, two Bison tractors were coupled together.

This gave a 140 horsepower (hk) four-wheel-drive machine with enormous tractive effort. The BM 471 Bison was BM’s first true four-wheel-drive tractor. It weighed 3 720 kg without the safety frame. The 471 did not turn out to be a major seller, but around fifty were made during 1962-63.

The 470 Bison was also used to pull dumper trailers. This symbolizes the development from red tractor to yellow construction machines which began at that time. Even so, many more tractors would leave the Eskilstuna factory.

The Bison was also used as platform for the production of both industrial tractors (470 I) and forestry machines.

In the new designation system, the successor to the Bison was called T 800.

BM 470 / BM 471 (Bison) specifications
Engine Bolinders 1114
Cylinders 4
Cylinder capacity, l 5,04
Rated output, hk  
– BM 470 73
– BM 471 75
Gears, forward/reverse 5/1
Wheelbase, mm  
– BM 470 2175
– BM 471 2400
Operating weight, kg  
– BM 470 3360
– BM 471 3720
Production no.
– BM 470 3695
– BM 470 I 474
– BM 471 50
Production year
– BM 470 1959-1966
– BM 470 I 1962-1966
– BM 471 1962-1963
281 281