When should the tractor’s differential be locked?
- When it is required to make a sharp turn on the spot while driving at a high speed.
- When the tractor struggles to tow or pull a heavy weight tool.
- When it is required to make a sharp turn on the spot while driving at a very slow speed.
- Correct answer: When one wheel skids on the ground and the tractor cannot proceed.
Why this is the answer
The correct answer in the official bank: When one wheel skids on the ground and the tractor cannot proceed.
The differential sends power to the wheel that turns most easily, so when one wheel skids on mud or soft ground it just spins and the tractor gets stuck. Locking the differential makes both wheels turn together and restores traction. Never turn with the lock engaged, since it stops the wheels from turning at different speeds and makes steering hard. Towing a heavy tool without wheel slip is not a reason to lock it.