When modern design and high-performance come together

Available in a 3.1m cutting width, the GMD 3125 F disc mowers are ideal for hilly ground, and perfectly adapted to medium-sized farms and agricultural contractors.


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Successful farms today aim to improve profitability. It is necessary to provide the herd with highly nutritional forage while aiming for feed self-sufficiency. Lowering the level of impurities from 4 to 2 % per year, means gaining 89€/ha/year (study from the Chamber of Agriculture of Weser Ems - Germany), an advantage in a difficult agricultural context. Farmers can count on the high performance and reliability of KUHN's front-mounted GMD 3125 to produce great quality forage. Hitch them to the tractor in combination with a triple GMD (GMD 8730 or GMD 9530) to increase work output.

Your Benefits

Top forage quality for the herd

LIFT-CONTROL hydro-pneumatic suspension produces clean forage

The hydro-pneumatic LIFT-CONTROL system with an accumulator replaces the traditional spring. The cutter is subject to rearward stress when working. When stress increases, the suspension system does too. This results in effective adaption to uneven ground. The sward is protected and less dirt gets into the swath.

A perfect cut with the OPTIDISC ELITE cutter bar

The new OPTIDISC ELITE cutter bar was developed with farmers. Variable spacing between the discs, large overlap zones and the reduced angle of the OPTIDISC cutter bar will provide you with the quality you need. The GMD 3125 F is equipped with this cutter bar and its latest upgrades that guarantee a clean cut at all times. The OPTIDISC ELITE cutter bar includes exclusive features:

  • Spacing is reduced at the point where the discs diverge to increase knife overlap. This results in a clean cut even in light or short grasses. (A)
  • Distance is increased at the point where the discs converge. This makes more space for the crop to pass through which is quickly carried away to the rear so that the mower can do its job undisrupted. (B)
  • The overlap zone is almost doubled resulting in better cutting quality in damp sticky ground (or with mole hills), in heavy and laying crops, and in plant cover harvested at the end of autumn.
  • A smaller pitch angle: this prevents the undulating cut which is typical with close mowing. It also stimulates homogeneous and faster regrowth and makes it easier to adjust the machines that follow.
  • New disc bearings with exclusive shape and attachment which hold the knives firmly in place in the event of impact while granting 360° rotational freedom.

Soil can build up in front of a cutter bar on hilly plots or in wet and sticky conditions, but not with the OPTIDISC ELITE cutter bar! It has specially designed skids to improve gliding and preserve the sward. Another advantage for forage quality, especially in difficult conditions.

Great forage in a narrow swath

GMD 1025 F mowers have swathing drums on both sides that reduce the width of the swath by 20 cm compared to a classic swath. The wheels of the tractor no longer run over the crop.

Good ground contour following

The front mowers have two strong lower link arms mounted on large ball joints. The pivot points, tractor-side, are closer to the ground than the front ones. This dynamic loading creates better ground clearance and makes the mower unit more stable and effective in ground contouring, especially on hilly terrain. The mowing unit integrates pendulum-type articulation so it is more flexible and adapts to uneven plots. The pendulum-type movement provides a maximum tilt of 30°. Articulated arms allow for up to 70cm of vertical clearance.

Save time and money

A mower to rely on at all times

The PROTECTADRIVE system is integrated into the cutter bar to withstand shocks and obstacles when mowing. In the event of a violent impact against one of the discs, the shaft holding the disc shears just above the bearing thanks to a carefully dimensioned shear groove. The gearwheels are protected. The machine is back up and running quickly and at a low repair cost.
The disc bearing stations are attached by long bolts that pass through the entire cutter bar. This eliminates any risk of the mounts being torn out of the cutter bar in case of impact.
Top-of-the-range components strengthen the centrepiece of the cutter bar:

  • Special disc-bearing station with a double row of angular contact ball bearings.
  • Large-diameter gear wheels in high-precision forged steel with 3 cogs engaged.
  • Discs with forged and heat treated cups over the whole surface area.
  • Disc skids in treated steel with the option of adding a protective layer (screw-on).

In order to lengthen the machine’s service life, shock absorbers are integrated in the connection between cutter bar and chassis. The structure of the machine is less affected by impacts, especially when working at fast ground speeds.

Quick maintenance with the FAST-FIT knife-attachment system

The GMD 3125 F mower is equipped with the FAST-FIT quick-release knife system as standard which provides 3 extra guarantees:

  • A powerful leaf spring provides constant pressure to the knife retainer: it is not restricted.
  • The knife retaining pins are also equipped with a shoulder to provide an additional level of securement.
  • The leaf spring can only be depressed to remove the knife at one point when the knife is centred over the shoe.

Therefore when the disc is rotating it is not possible for the knife to be released. To minimise costs the knife retention pin can be replaced separately from the leaf spring.
Cutting quality remains excellent owing to the compactness of the cutter bar and the exclusive shape of the blades which rotate as close as possible to the protective skids.

A flexible side guard protects against impact

The rubber side guard FLEXPROTECT can bend on impact without breaking or damaging the mower, before returning to its initial shape. This exclusive guard will save you money on repair costs.

A mower that adapts to your plot

Benefit from a wide overlap that can adapts to your plot

Front mowers can be used in combination with rear GMD mowers. Overlap width can be modified by 19cm with the offset of the rear GMD 1011 series model to create a clean cut on slopes and bends. It is possible to obtain an overlap of between 240 and 645 cm depending on the rear hitch and working width of the front unit. This is an advantage when using wide-track tractors or with wide tyres.

Quick and easy adjustments

Operating comfort is one of KUHN’s priorities. On GMD 3125 F and 3525 F mowers, ground pressure is quick and easy to adjust with hydraulic suspension that maintains it at the right level. The mowing units are lifted at headlands with an integrated cylinder so the tractor’s hydraulic front lift system is not used.

Easy maneuvering and good visibility

A transport width of 3.00m makes the machines easier to handle, especially on the road. Optional wing mirrors are available for safer road travel.


Technical characteristics

GMD 3125 F-FF
Working width (m)3.1
Transport width (m)2.99
Number of discs with wear skids7
Disc wear skid2 as standard
Blade attachmentFAST-FIT quick release
Cutting height range with standard skids (mm)35 to 65
Gear train protection systemPROTECTADRIVE safety system
Ground followingPivoting link rods with upward movement
SuspensionLIFT-CONTROL hydro-pneumatic suspension
Headland turning positionby hydraulic cylinder
Average swath width (m)1 - 1.2
Swathing system2 PTO driven drums
Hitch3 point Cat 2
PTO speed (min-1)1000 (left or right of rotation) - factory setting - to the right (seen from the tractor seat)
Overload protectionfriction slip clutch
Free wheelintegrated into the side gearbox
Theoretical tractor power requirement (kW/hp)32/43
Required tractor hydraulic connections1 SA
Required tractor electrical connections7 pin-plug
Road lights and signalling on front and rearas standard
Approx. weight (kg)1105