Lower Link
The two lower connecting arms of the three-point linkage that carry the implement's draft load. They are attached with joints to the tractor's rear body, the implement hitch pin passes into the pin socket at their end, and they receive the hydraulic lifting force through the lift rod. The pin diameter varies between 17 and 37.4 mm depending on the three-point linkage category.
The lower links are the load-carrying side of the linkage: almost all of the draft force generated in tillage is transferred to the tractor body through these two links. The lifting force, on the other hand, does not come to the lower link directly but from the lift arm through the lift rod. That is why there is no cylinder on the lower link itself; the link only carries and directs the force.
- Lateral swing is limited by a sway stabiliser or chain; otherwise the implement swings about on the road.
- Systems that measure the load on the lower link pins perform lower-link draft sensing.
- A worn pin socket creates play; implement depth wanders and work quality drops.
When you fit an electronic retrofit kit, the lower link is not touched at all. The LFT20 and LFT54 operate the existing mechanism through the cable; the movement of the links still comes from the tractor's own hydraulics. Therefore depth deviations caused by link play, a worn pin or a loose stabiliser are not corrected by electronic control — those are mechanical maintenance matters.
Context in which this term is used: Converting a tractor hydraulic lever to electronic control