Why Implement Leveling Matters Before You Start Working
A 3 point hitch that lifts and lowers reliably is only half the job. The other half is making sure the implement arrives at the working position with its cutting edge, tillage blades, or seeding row exactly parallel to the ground surface. An implement that tilts nose-down digs in on one side and skips on the other. An implement that leans left or right leaves uneven working depth across its width. Both problems waste fuel, damage crops or soil, and put uneven stress on hitch pins, lift arms, and the implement’s own frame.
Adjusting the top link and the lower links correctly is the primary method for setting implement level. These two adjustments are independent and address different axes of tilt. This guide explains what each link controls, how to make the adjustments, and what to check before you commit to a full field pass.
What the Top Link Controls: Fore-Aft Tilt
The top link is the single diagonal arm that connects from a bracket on the tractor’s upper hydraulic housing to a pin point near the top of the implement’s frame. Its job is to control the fore-aft (front-to-back) angle of the implement relative to the ground — sometimes called the implement’s pitch angle or working angle.
Shortening the top link
Shortening the top link pulls the top of the implement toward the tractor, which tilts the implement’s bottom edge away from the tractor — a nose-down or front-edge-down position. For tillage implements such as a rotary tiller or chisel plow, this angle increases working depth at the front of the implement and tends to make it pull itself deeper into the ground under draft load. For a box blade or land plane, nose-down means the leading edge cuts more aggressively. Use this setting when you want the implement to self-feed into the ground or when soil conditions require more aggressive attack angle.
Lengthening the top link
Lengthening the top link pushes the top of the implement away from the tractor, bringing the bottom leading edge up — a nose-up or rear-edge-down position. This reduces working depth at the front and often produces a shallower, more level tillage pass. For rotary tillers, a slightly nose-up attitude places more blade load on the rear tines, which produces a finer, more uniform finish. For post hole diggers and other vertical tools, exact vertical attitude is critical — adjust top link until a spirit level placed on the implement frame reads level fore-to-aft.
What the Lower Links Control: Lateral Level
The two lower links are the primary load-bearing arms that carry the implement’s weight through the hitch. At the tractor end, each lower link attaches to a lift arm. The relationship between the two lower links — their individual height positions and the length of the leveling box or check chain on one side — determines whether the implement hangs level side-to-side.
Using the leveling box (right-hand side adjustment)
Most tractors have a fixed-length lower link on the left side and a leveling box (sometimes called a turnbuckle or right-hand link adjuster) on the right side. Turning the leveling box shortens or lengthens the right lower link, raising or lowering the right side of the implement. With the tractor parked on level ground, lower the implement to working depth with a spirit level placed across the implement frame, then adjust the leveling box until the frame reads level. This is the standard procedure for any implement wider than approximately one meter.
Check chains and sway control
Check chains (also called sway chains or stabilizer chains) connect from the lower links to brackets on the tractor’s rear axle housing. Their purpose is to limit lateral sway of the implement during transport — not to adjust working level. When set correctly, check chains should have a small amount of slack when the implement is centered behind the tractor, tightening only if the implement swings significantly to one side. Check chains that are too tight prevent the implement from following ground contours and can bend lower link hitch pins under sideways soil load.
Step-by-Step Adjustment Procedure
Follow this sequence every time you attach a new implement or move an implement between tractors.
Park on level groundAll adjustments must be made with the tractor and implement on a flat, level surface. Adjusting on a slope introduces a measurement error that will not be apparent until the implement runs in the field.
Lower to working depthHydraulically lower the 3 point hitch until the implement is at its intended working depth — or for non-soil implements, at the height it will operate. Do not adjust level at full raised height; the implement’s geometry changes slightly as the hitch lowers.
Check lateral level firstPlace a spirit level across the implement frame, perpendicular to the direction of travel. Adjust the leveling box (right-hand lower link) until the implement reads level side to side. Lock the leveling box adjustment when correct.
Adjust fore-aft angle with top linkPlace the spirit level along the implement frame, parallel to the direction of travel. Shorten or lengthen the top link until the implement reaches the correct working angle for its type. For most tillage implements, level to very slightly nose-down is a good starting point.
Make a short test pass and inspectDrive one pass of approximately 10 metres, stop, and inspect the soil or cut pattern. Look for uneven working depth left-to-right (lateral level error) or uneven depth front-to-back (fore-aft tilt error). Make small corrections and repeat until the implement works evenly across its full width.
Common Mistakes and How to Avoid Them
| Mistake | Effect | Correction |
|---|---|---|
| Adjusting on sloped ground | False level reading; uneven field work | Always park on flat concrete or packed level soil |
| Using check chains to level laterally | Bent hitch pins, restricted implement movement | Use leveling box for lateral level; chains for transport sway only |
| Adjusting level at raised transport height | Geometry shifts at working depth — implement not actually level | Always adjust at intended working depth |
| Excessively short top link | Implement nose-dives in soil, excessive draft load | Lengthen top link gradually until working angle is correct |
| Not checking after changing soil conditions | Hard vs. soft ground changes implement attitude under draft | Re-check and fine-tune level when field conditions change significantly |
Lift Arm and Hitch Pin Condition Affects Adjustment Accuracy
Even correct top link and lower link settings cannot compensate for worn or bent hitch components. Worn lift arm bushings allow the lower links to sag or swing laterally under load, meaning the implement’s actual working position does not match the adjusted position. Bent lower link hitch pins introduce twist that makes level adjustments inconsistent across the lift range. Before spending time on top link and leveling box adjustments, inspect all hitch pins for straightness, check the lift arm bushings for excessive play, and verify that the lower link balls seat correctly in the implement’s hitch hook or quick coupler.
Browse our 3 point hitch kit replacement parts to find compatible lift arms, hitch pins, and leveling box components for major tractor brands including John Deere, Kubota, and Massey Ferguson. Confirm your tractor’s hitch category before ordering to ensure pin diameter and ball size match.
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