In which of the following cases is it not recommended to turn on a differential lock in an agricultural tractor?
Show the correct answer
Correct answer
B. While driving on a winding road.
Explanation
This question is about situations in which you should not switch on the differential lock in a tractor. You do not switch it on when driving on a winding road - answer B.
The lock connects the wheels of one axle so that they turn at the same speed. On boggy terrain (answer A) and during field work (answer C), when one wheel loses grip and spins, this is exactly what allows the tractor to keep moving - this is what the lock is for. On a winding road, the outer wheels must turn faster than the inner ones; with the lock switched on, one of them slides over the road surface, stresses in the half-shafts and the differential increase, the tyres wear quickly, and the tractor resists turning and easily runs wide out of the bend. That is why, before driving onto the road and before every bend, you check that the lock is switched off - in many tractors a warning light shows this.
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