3 Point Linkage
Three point linkage (or three-point-hitch) is a standardised system to attach implements to tractors. They comprise of three movable arms assembled in a triangle or ‘A’ formation, and are controlled by the hydraulic system allowing lifting, lowering and tilting. Three point linkage systems are designed to shift the weight of the implement, such as a plough, to the tractor providing the tractor more traction. The top link (upper centre arm) is adjustable in length to allow the attachment to run at the desired level. In most instances, the top link will also actuate the tractors built in ‘draft control’. Draft control is a system that adjusts depth automatically when resistance, eg. A stone or root is met by a ground engaging implement.
The orientation of the implement can be altered longitudinally by adjusting the ‘levelling box’ and laterally by adjusting the top link. Stabilisers can be fitted and adjusted to reduce implement ‘sway’, normally to avoid the implement fouling the tyres when traveling.
Top Link
The top link is rigid and is designed to set the operating angle alignment of the implement. Manual top links have an adjustable shaft with a ‘ball’ end – one end is attached to the tractor and the other to the implement. Hydraulic top links are common on large machines, these allow adjustments to be made with ease at the touch of a button!Lower Lift Arm
The lower lift arms are two rigid bars with ball joints each end. Powered by the hydraulic system and controlled by the driver, the lower lift arms are the only powered part of the 3 point linkage, designed to lift and lower any implement attached to them.
The Ferguson System
The 3 point linkage system was patented in the UK by Harry Ferguson in 1926, this was known as ‘the Ferguson System’ and included a range of purpose built agricultural implements. The Ferguson System revolutionised farming, mounting an implement, rather than towing it enabled tractors to carry a vast array of implements with improved safety, traction and all-round efficiency.
At Anglo Agriparts we provide a wide variety of linkage parts and implements. To include, linkage kits, link arms, drop arms, levelling boxes, top links, lynch pins and clips
3 Point Hitch Specification
Linkage is categorised by the size of your tractor's engine. Selecting the appropriate category will enable the implement to be attached securely and safely.
| Category | Application | Hitch Pin Size - Upper Link | Hitch Pin Size - Lower Link | Lower Hitch Spacing | Tractor Drawbar Power |
|---|---|---|---|---|---|
| 0 | Suitable for lightweight implements on compact tractors and small ride on mowers. | 17 mm (5⁄8") | 17 mm (5⁄8") | 500 mm (20") | <15kW (<20 hp) |
| 1 | Suitable for compact tractors under 50 hp. | 19 mm (3⁄4") | 22.4 mm (7⁄8") | 718 mm (28") | 15-35 kW (20-45 hp) |
| 2 | Suitable for utility tractors between 50-140 hp. | 25.5 mm (1") | 28.7 mm (1 1⁄8") | 870 mm (34") | 30-75 kW (40-100 hp) |
| 3 | Suitable for large tractors between 110-220 hp. | 31.75 mm (1 1⁄4") | 37.4 mm (1 7⁄16") | 1010 mm (40") | 60-168 kW (80-225 hp) |
| 4 | Suitable for heavy duty tractors with engines over 180 hp. | 45mm (1 3⁄4") | 51 mm (2") | 1220 mm (48") | 135-300 kW (180-400 hp) |
Whilst we strive to provide accurate data, on occasion information may be omitted or inaccurate. Please contact us at admin@anglo-agirparts.com if you identify an error or omission. Always consult official service manuals from the manufacturer before attempting any service or repair.
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