Designated use of the machine The GMD350 mower must only be used for the purpose for which it was manufactured: mowing on the ground of hay fields, grass silage fields and improved pastures for the purpose of harvesting fodder for feeding livestock.
Disc mower GMD350 - 350-FF $Contents Dear Owner ........................1 Contents..........................2 Identification of the machine..................4 Front view............................4 Rear view............................4 Model identification plate ........................5 Optional equipment..........................5 Safety..........................6 Description of symbols used in this document................6 Safety instructions ...........................7 Location and description of safety decals on the machine ............18 Road safety equipment and recommendations................22...
Page 5
Disc mower GMD350 - 350-FF Instructions for work ....................46 Putting the machine into work position ..................46 Adjustments in working position....................48 Machine use............................ 52 Optional equipment ..................... 56 Chain stroke limiter........................56 Outer guard hydraulic locking ...................... 57 Side deflector..........................
Disc mower GMD350 - 350-FF 3. Model identification plate Please write below the type and serial number of the machine. This information is to be indicated to the dealer for all spare parts orders. GMD350 Type: Serial no.: 4. Optional equipment...
Disc mower GMD350 - 350-FF $Safety 1. Description of symbols used in this document This symbol indicates a potentially hazardous situation that if not avoided, could result in serious bodily injury. This symbol is used to identify special instructions or procedures which, if not followed strictly, could result in machinery damage.
Never let anyone operate the machine who is not trained to do so. Should you have any difficulties in understanding certain parts in this manual, please contact your KUHN dealer. Precautions to be taken before carrying out any operations on the machine...
Page 10
Disc mower GMD350 - 350-FF Precautions to take before using the machine Do not wear loose clothing which could become caught up in moving parts. Wear the appropriate protective clothing for the work in hand (gloves, shoes, goggles, helmet, ear defenders, etc.).
Page 11
Disc mower GMD350 - 350-FF Precautions when driving on public roads Dimensions Depending on the dimensions of the machine, contact the relevant authorities to ensure that it can be legally transported on public roads. If the machine is over the maximum legal size, follow the local regulations for special transportation of oversize equipment.
Page 12
Disc mower GMD350 - 350-FF For machines with hoppers or tanks: - If the total unit weight exceeds the tractor Gross Combined Weight Rating in accordance with the countrie's legislation, empty the hopper to travel on public roads. - In any case, we recommend to travel on public roads with empty hoppers and tanks.
Page 13
Disc mower GMD350 - 350-FF Stage 2: - Couple the machine to the tractor. To measure: - Load on front axle (t1): • Tractor + machine (transport position). To do: - If the front axle load (t1) is below 20% of the tractor tare (T), add ballast weights (M1) to exceed the minimum load on the front axle.
Page 14
Disc mower GMD350 - 350-FF Stage 4: To measure: - Load on rear axle (t2): • Tractor + machine (transport position). • Ballast weights. Checking: - Check in the tractor's operator's manual that the value measured is below the maximum allowed tractor rear axle load.
Page 15
Disc mower GMD350 - 350-FF Precautions when coupling Before attaching the machine, make sure that it cannot accidentally start moving (chock the wheels) and that the parking stand is in the right position. The machine must only be attached to the hitch points provided for this purpose.
Page 16
Disc mower GMD350 - 350-FF PTO shaft Use only PTO shafts supplied with the machine or recommended by the manufacturer. The protective shield of the tractor PTO stub, the PTO shaft guards and the protective covering of the machine input shaft must always be in place and in good condition.
Page 17
Disc mower GMD350 - 350-FF Precautions during manoeuvres When moving the machine from the transport position to the working position and vice versa, make sure that nobody is within the machine pivoting area. Remote controlled components Danger of crushing and shearing can exist when components are operated by hydraulic or pneumatic controls.
Page 18
For your own safety and for correct machine operation, only use original manufacturer parts. It is strongly recommended to have your machine checked by your Kuhn dealer after each season, especially tools and their attaching hardware. Projection of stones and foreign objects For driver safety, always use a tractor equipped with a cab.
Page 19
Disc mower GMD350 - 350-FF The protection covers help reducing risks of projections. Therefore, make sure that all mower protection devices are in place and good condition prior to using the machine. Regularly check the condition of the protection covers.
Disc mower GMD350 - 350-FF 3. Location and description of safety decals on the machine Location of safety decals Safety...
Page 21
Disc mower GMD350 - 350-FF Description of safety decals Operating instructions (1) The operators' manual contains all the information necessary for using the machine safely. It is imperative to read and comply with all instructions. Working on the machine (2)
Page 22
Disc mower GMD350 - 350-FF Crushing area (4) Never operate in an area where there is a crushing risk before all moving parts have come to a complete stop. Manoeuvring area (5) Stay a safe distance from the machine. Crushing hazard.
Page 23
Disc mower GMD350 - 350-FF Do not step on the machine (8) Do not step on the machine : Risk of falling or damaging the protection device. Ground pressure cylinder locking (9) The ground pressure cylinder valve must be shut off prior to uncoupling the machine.
GMD350 - 350-FF 4. Road safety equipment and recommendations The road safety equipment is mounted in the factory or by your authorized Kuhn dealer according to current safety regulations. The device is composed of: - 1 red reflector (1). Always keep to the legal speed limit for driving a tractor- machine assembly on public roads.
Disc mower GMD350 - 350-FF 2. Technical specifications Attachment type 3 point, Category 2 Number of discs Working width 3.50 m (11’5’’) Width in working position 5.34 m (17’6’’) Height in working position 1.39 m (4’6’’) Length in working position 1.29 m (4’3’’)
Disc mower GMD350 - 350-FF 3. Required equipment The machine is factory fitted with the following equipment: Put into the working or transport position - Mechanical safety release. - Mechanical safety release + Hydraulic pivot. Machine specifications...
Disc mower GMD350 - 350-FF Cutter bar - Knife attachment per bolt and nut. - Fast fit knives. 4. Sound levels Sound levels have been measured in accordance with the measuring methods as defined in: NF EN ISO 4254-1 «Agricultural machinery - Safety - Part 1: General requirements»...
Disc mower GMD350 - 350-FF $Putting into service 1. Description of control elements The machine is fitted with a release cord operated from the tractor cab. The machine is supplied with an 18 mm box wrench (1) to carry out certain adjustment and maintenance tasks.
Disc mower GMD350 - 350-FF 2. Coupling and uncoupling The machine adapts to tractors fitted with a 3 point linkage category 2. Description of coupling elements - A PTO shaft 1 3/8’’ - 6 splines (1). - A release cord (2).
Page 31
Disc mower GMD350 - 350-FF Preparing the tractor Check that the tractor's authorized gross weight as well as its lift capacity and maximum weight per axle are not exceeded. The front axle load (1) must never, under any circumstances, be less than 20% of the tractor's unladen weight.
Page 32
Disc mower GMD350 - 350-FF Preparing the machine Positioning of lower links - Measure dimension E. - Adjust tractor lower link stabilizers to measure E = 50 mm (2"). Linkage adjustment - Measure dimension A. If measure A is below 2.10 m (6’11’’):...
Page 33
Disc mower GMD350 - 350-FF If measure A is comprised between 2.10 m (6’11") and 2.25 m (7’04"): - Place lower links in position b: Adjust machine lower hitch pin position: - Loosen the 8 screws (3). - Centre hitch pin (1) with regards to the mounting plate.
Page 34
Disc mower GMD350 - 350-FF Pressurizing the hydraulic ground pressure circuit The machine hydraulic ground pressure circuit is factory set without pressure. The optimal suspension is obtained with the mowing unit ground pressure set to the minimum, in such a way that the unit does not lift off the ground when going over irregular ground contours.
Page 35
Disc mower GMD350 - 350-FF Coupling the machine - Lower the tractor three-point linkage. - Position ball joints of tractor lower links in line with machine lower yokes. - Attach the lower links to the hitch pins. - Secure each hitch pin with lynch pin.
Page 36
Disc mower GMD350 - 350-FF - Raise and lock parking stand (1). The following procedure puts the machine mechanism under tension and balances plays in the tractor-mechanism coupling links. Prior to opening the ground pressure circuit valve: - Attach the lower links to the hitch pins.
Page 37
Disc mower GMD350 - 350-FF The machine is properly attached when the following conditions are respected: - Pivot pin (1) is vertical. If pivot pin (1) is not vertical: - Adjust and lock the tractor turnbuckles. • Fully lift tractor lift linkage.
Page 38
Disc mower GMD350 - 350-FF Electrical connection Lighting and signalling: When the following equipment is fitted: Mechanical safety release + Hydraulic pivot Lighting and signalling: - Connect 7-pin plug to the tractor. When the following equipment is fitted: Mechanical safety release...
Page 39
Disc mower GMD350 - 350-FF Primary PTO shaft Make sure that the PTO shaft is correctly adjusted, to avoid premature wear and tear. The tractor PTO stub must rotate at a speed of 540 min Separate the two half PTO shafts and connect them to the machine's input shaft and to the tractor PTO stub.
Page 40
Disc mower GMD350 - 350-FF On machine side, attach guard chain to the main frame. Immediately replace any worn or damaged guard. Adjusting the machine Frame height Tractor fitted with a hydraulic position control function: - Lower tractor lift linkage in order to engage lift stop (1) in its housing.
Page 41
Disc mower GMD350 - 350-FF Uncoupling the machine - Activate the transport/work cylinder to bring the mowing unit in working position. - Fully lift tractor lift linkage. - Shut-off the mowing unit ground pressure circuit valve (1) using 18mm box spanner.
Page 42
Disc mower GMD350 - 350-FF - Uncouple the PTO shaft. - Place PTO shaft in holder (1). When the following equipment is fitted: Mechanical safety release + Hydraulic pivot - Disconnect and store hydraulic hoses in holder (1). - Disconnect and store lighting equipment 7- pin plug in its holder (1).
Page 43
Disc mower GMD350 - 350-FF - Remove cord from tractor and store it in its holder on the machine (1). - Detach the top link from the machine end. - Release the lower links. The machine is uncoupled. Always park the machine with the cutter bar in horizontal position.
Page 44
Disc mower GMD350 - 350-FF When the following equipment is fitted: Mechanical safety release + Hydraulic pivot Adjusting the pivot sequence of the machine The machine pivot sequence when putting the machine into work/transport position is obtained by adjusting cam (2).
Disc mower GMD350 - 350-FF $Instructions for transport Before placing the machine into transport position: Wait until the rotating parts have come to a complete stop. Check that nobody is located in the machine pivoting area. If there is someone, make sure the person moves away.
Disc mower GMD350 - 350-FF - Activate the transport/work cylinder to bring the mowing unit in transport position. - As cutter bar is being pivoted, wait until lift stop end (1) passes over lock (2) and release cord. The machine automatically locks in transport position.
Page 47
Disc mower GMD350 - 350-FF Make sure that transport lock (1) is fully engaged. Instructions for transport...
Disc mower GMD350 - 350-FF $Instructions for work Before placing the machine in working position: - Check that nobody is within the machine pivoting area. - If there is someone, make sure the person moves away. 1. Putting the machine into work...
Page 49
Disc mower GMD350 - 350-FF When the following equipment is fitted: Mechanical safety release - Unlock and lower the front guard using 18mm box spanner supplied with the machine. • The guard locks automatically. - Unlock and lower side guard.
Disc mower GMD350 - 350-FF 2. Adjustments in working position Before leaving tractor before adjusting, maintaining or repairing the machine, disengage the PTO drive, turn off the engine, remove ignition key and wait until all moving parts have come to a complete stop and apply park brake.
Page 51
Disc mower GMD350 - 350-FF - Open the suspension circuit valve. Ground pressure circuit valve: - Valve open (a) - Valve closed (b) The maximum cutting height (L1 = 60 mm (2.4’’)) is obtained when the discs are parallel to the ground.
Page 52
Disc mower GMD350 - 350-FF To check the ground pressure:: - Place the machine in working position. - Lower tractor lift linkage until obtaining a distance of 450 mm (1’5’’) between the hitch pin pivot point and the ground. - Check the pressure given on the gauge: Conventional pressure = 105 bar (psi).
Page 53
Disc mower GMD350 - 350-FF Reduce the hydro-pneumatic accumulator pressure to increase the mowing unit ground pressure - Place the machine in working position. - Shift the mowing unit lift cylinder directional control valve in float position. - Open valve (1) of hydraulic valve bank using 18mm box spanner supplied with the machine.
Disc mower GMD350 - 350-FF 3. Machine use Before mowing and to reduce risks of projections, lower the front guard. Keep all persons and animals away from the machine danger zone. When the following equipment is fitted: Mechanical safety release...
Page 55
Disc mower GMD350 - 350-FF Headland turn maneuvers Operate the cutterbar using the "pivot into transport/work" position cylinder. - Activate the transport/work cylinder control valve in the "pivot into transport" position. • The cylinder lock (1) bottoms. When the following equipment is fitted:...
Page 56
Disc mower GMD350 - 350-FF Machine safety When hitting an obstacle: Before carrying out any maintenance or repairs on the machine, switch off the tractor engine, remove ignition key, wait until all moving parts have come to a standstill and apply park brake.
Page 57
Disc mower GMD350 - 350-FF If the break-away latch releases too easily after reset, tighten nut (1) to increase spring washer compression slightly. Respect spring washer layout. Basic adjustment: L= 95 mm (3.7’’) For normal functioning of the break-away latch, measure L must never be below 91 mm (3.60").
Disc mower GMD350 - 350-FF $Optional equipment 1. Chain stroke limiter Kit no. 1066090 This equipment enables adjusting the chassis height in the absence of a hydraulic stroke limiter with position indexation on the tractor. Adjusting the machine Frame height adjustment - Lower tractor lift linkage until hitch pins are at a distance H slightly over 450 mm (1’5’’) from the...
Disc mower GMD350 - 350-FF 2. Outer guard hydraulic locking Kit no. 1066100 Available for the following models: - Mechanical safety release + Hydraulic pivot. This equipment enables folding the machine outer guard using the hydraulic control. Coupling and uncoupling...
Disc mower GMD350 - 350-FF 3. Side deflector Kit no. 1066150 The side deflectors enables mowing dense or down crops with long stems. Fit the side deflector on the cutter bar right attachment (1). Optional equipment...
Disc mower GMD350 - 350-FF 4. 1000 min drive kit Kit no. 1066170 Belt and pulley assembly for tractors with a pto speed of 1000 min 5. Adaptation parts Part no. 56842400 + Part no. 80451046 This equipment enables coupling the machine to a U- frame hitch coupler ( ISO 11001-1 ) ( Quick hitch ).
Disc mower GMD350 - 350-FF $Maintenance and storage Before carrying out any maintenance or repairs on the machine, switch off the tractor engine, remove ignition key, wait until all moving parts have come to a standstill and apply park brake.
Page 64
Disc mower GMD350 - 350-FF Grease: When the following equipment is fitted: Mechanical safety release + Hydraulic pivot The cylinder crosshead: Grease the crosshead inside: - Loosen nut (1) to release lock (2). - Grease the cylinder tube and sheath inner.
Page 65
Disc mower GMD350 - 350-FF - The chassis lever (1 greaser). Oil: - The moving parts and pivot points. Maintenance and storage...
Page 66
Disc mower GMD350 - 350-FF - The moving parts and pivot points. Maintenance and storage...
Page 67
Disc mower GMD350 - 350-FF Oil change: Gearbox Before draining oil, operate the machine for a few minutes so that the oil warms up. The angle gearbox is lubricated with 0.5 L (0.13 US gal) of SPIRAX A extreme-pressure oil for mechanical transmissions with viscosity grade SAE 80W90 and API grade GL5.
Disc mower GMD350 - 350-FF 3. Maintenance Before carrying out any maintenance or repairs on the machine, switch off the tractor engine, remove ignition key, wait until all moving parts have come to a standstill and apply park brake. Belt tension Regularly check belt tension and in particular during the first hours of use.
Page 69
Disc mower GMD350 - 350-FF Hydro-pneumatic accumulator Before any work is carried out on a hydraulic circuit with hydro-pneumatic accumulator, depressurize the circuit. It is strictly forbidden to weld, grind or drill onto a hydro-pneumatic accumulator. The hydro-pneumatic accumulator does not require any particular maintenance.
Page 70
Disc mower GMD350 - 350-FF Cutterbar The cutter bar is lubricated for life and does not require regular maintenance. If in doubt as to the oil quantity contained in the cutterbar, fully drain and refill cutterbar respecting recommended oil quantity and quality.
Page 71
Disc mower GMD350 - 350-FF - Activate the transport/work cylinder control valve in the "pivot into transport" position. - Place a container of sufficient capacity under drain plug. - Remove the inner skid shoe (1) on drive side. - Unscrew drain plug (1) and its seal.
Page 72
Disc mower GMD350 - 350-FF Check angle gearbox oil level Regularly check the oil level: - Place the cutterbar in horizontal position. - Remove drain plug (1). - Check the oil level. - Top up if necessary. - Clean and reinstall drain plug (1). Replace it if necessary.
Page 73
Disc mower GMD350 - 350-FF Inspection of knives and securing elements Immediately replace worn or damaged parts with genuine KUHN parts. When the following equipment is fitted: Knife attachment per bolt and nut Knives Inspect systematically all knives before the machine is operated to: - guarantee the cutting quality.
Page 74
Disc mower GMD350 - 350-FF Fixing elements Check the fixing elements: - After hitting an obstacle. - When replacing knives. - At the beginning of each season. The fixing bolts should be changed in the following cases: - When there is visible distortion.
Page 75
Disc mower GMD350 - 350-FF Knife replacement Replace knife lock-nuts and bolts when they have been removed 5 times. Replace immediately all worn or distorted knives. Never straighten a bent knife. Always replace both knives per disc. - Clean the nut case.
Page 76
Disc mower GMD350 - 350-FF Check if there is still a gap of 1 mm (0.04’’) between the disc lower part and the cutterbar wear plates. If this is not the case, fit one (maximum two) spacer(s) between the disc and the mounting hub: - (Part no.
Page 77
Disc mower GMD350 - 350-FF When the following equipment is fitted: Fast fit knives Knives Inspect systematically all knives before the machine is operated to: - guarantee the cutting quality. - guarantee safety in use. - Prevent cutterbar damage risks.
Page 78
Disc mower GMD350 - 350-FF Fixing elements Check the fixing elements: - After hitting an obstacle. - When replacing knives. - At the start of each season. The fixing bolts should be changed in the following cases (2): - When there is visible distortion.
Page 79
Disc mower GMD350 - 350-FF Replace nuts in the following cases: - When nut wear reaches a = 5 mm (0.2’’). Check the condition of the fixing elements regularly and also the torque of the knife-fixing bolt: - Torque: 12 daN m (89 lbf ft).
Page 80
Disc mower GMD350 - 350-FF Knife replacement Before carrying out any maintenance or repairs on the machine, switch off the tractor engine, remove ignition key, wait until all moving parts have come to a standstill and apply park brake. Replace immediately all worn or distorted knives.
Page 81
Disc mower GMD350 - 350-FF - Make sure that the securing nut and bolt are in good condition and if necessary, replace them. • Torque: 12 daN m (89 lbf ft). Bolt: Part no. K6801011. Nut: Part no. 80201262. Dull knives require more horse power and have a negative effect on the cut quality.
Page 82
Disc mower GMD350 - 350-FF Disc replacement - Place a wooden wedge (1) between two discs to stop them from moving. - Remove the 4 bolts (2) and their conical washers. - Remove disc cover (1). - Remove the disc (2).
Page 83
Disc mower GMD350 - 350-FF - Reinstall bolts (1) and their conical washers. - Position conical centre of washers at the top. - Torque bolts to (1) : • Torque: 12 daN m (89 lbf ft). - Remove locking piece.
Page 84
Disc mower GMD350 - 350-FF Check that there is a minimum play of 1 mm (0.04’’) between the spring plate and the cutter bar skids. Otherwise, position spacer(s) (two maximum) between the housing and the spring plate - (Part no. 56807100).
Page 85
Disc mower GMD350 - 350-FF Spring plate replacement Inner disc: The replacement of the inner disc spring plate must be carried out by a Kuhn authorized dealer. Intermediate discs: - Remove the disc: • See section: ’’Disc replacement’’. - Remove spring plate (1).
Disc mower GMD350 - 350-FF 4. Storage At the end of each season - Clean the machine thoroughly. - Drain bevel gearbox and fill with new oil. - Touch up any areas of damaged paintwork. - Store machine with the cutter bar in horizontal position in a sheltered dry place.
Disc mower GMD350 - 350-FF $Trouble shooting guide Problem Cause Remedy Dull or broken knives. Replace knives. Make sure the arrow on the Knives not installed correctly. knife upper face is pointing in the disc's direction of rotation. Uneven stubble.
Page 88
Disc mower GMD350 - 350-FF Too frequent safety breakback Insufficient spring washer Increase spring washer release. compression. compression. When the following equipment is fitted: Mechanical safety release + Incorrect cam adjustment. Adjust machine pivot moment. Hydraulic pivot Interference between tractor and front guard.
Page 89
Disc mower GMD350 - 350-FF $Appendix 1. Calculating the load on an axle When coupling a tool to the front and rear 3-point lift linkage, the maximum authorized payload must not be exceeded. The load on the tractor front axle must always represent 20 % of the tractor unladen weight.
Page 90
Disc mower GMD350 - 350-FF Rear tool or front-rear combination: 1) Calculation of the minimum front ballast weight M1 minimum M2 x (c+d) - T1 x b + 0.2 x T x b minimum Write the minimal additional weight in the chart.
Page 91
Disc mower GMD350 - 350-FF Table: Actual value obtained Value authorized Double value of the by calculation according to authorized capacity operator's manual per tyre (2 tyres) Minimum front/rear ballasting kg ≤ Total weight kg ≤ kg ≤ Load on front axle kg ≤...
Page 92
Disc mower GMD350 - 350-FF Determining the machine weight (M2) and the position of its centre of gravity (d) If the data required to calculate the total weight, axle loads and minimum ballasting are not supplied, use the following method.
Page 94
Disc mower GMD350 - 350-FF Rear tool or front-rear combination: If the total unit weight exceeds the tractor Gross Combined Weight Rating in accordance with the countrie's legislation, empty the hopper to travel on public roads. In any case, we recommend to travel on public roads with empty hoppers and tanks.
Need help?
Do you have a question about the GMD350 and is the answer not in the manual?
Questions and answers