While driving an agricultural tractor on a winding road, is it recommended to turn on a differential lock?
Show the correct answer
Correct answer
B. No, because it may damage the mechanism.
Explanation
This question is about switching on the differential lock while driving a tractor on a road with many bends. This is not recommended, because the mechanism may be damaged - answer B.
On a bend, the outer wheel travels a longer distance than the inner one, so it must turn faster - this is exactly what the differential makes possible. The lock forces both wheels to turn at the same speed: on a bend one of them has to slip, high stresses build up in the drive system, the tyres wear quickly, and the differential and the half-shafts may be damaged. In addition, a tractor with a locked differential is reluctant to turn and "pushes" straight on, which on the road risks driving into the opposite lane or into a ditch. Answers A and C are wrong - a low speed does not remove this problem. You use the lock only on difficult terrain, driving straight, and switch it off before every turn.
Legal basis: Art. 19 para. 1 of the Road Traffic Act (Prawo o ruchu drogowym) (the principle of keeping control of the vehicle); operating rules from the tractor's owner's manual