2026 John Deere Ag R990M 

2026 John Deere AG R990M

Mower-Conditioners and Mounted Mowers

More Options to Put up Quality Hay

When it comes to cutting hay, John Deere has you covered. Whether you need a side-pull, center-pivot or front- or rear-mounted mower-conditioner, we’ve got the machine for you.

Cover more acres, with greater tractor compatibility and Quick Change Knives. All with the newly redesigned John Deere Zero Series Mower-Conditioners.

Time is critical when it comes to mowing and drying down your hay crop. Now you can get more done and produce high quality hay with the new John Deere Zero Series Mower-Conditioners. Cover more acres per hour with the new C500 Mower-Conditioner. The new lighter weight C400 Mower-Conditioner gives you a wider range of tractor compatibility, and increased ability to customize your windrow. All with the newly redesigned John Deere Zero Series Mower-Conditioners.

More Acres Per Hour

Get more done in a day with the new John Deere C500 Mower Conditioner. The 16 ft. 4 in. (5 m) cutting width of the new C500 lets you cover up to 10% more acres per hour.

Increased Tractor Compatibility

Now you can mow with a wider range of tractors and handle hills easier, due to the lighter weight of the John Deere C400 Mower-Conditioner. In addition to the flexibility to use lower horsepower tractors, you get wider conditioning rolls, Quick Change Knives and continued great maneuverability and durability with swivel hitch options.

Save Time with Quick Change Knives

Cut your time changing knives in half* with the Quick Change Knives, available on the redesigned John Deere Zero Series Mower-Conditioners, letting you spend less time servicing your mower and more time cutting hay. Changing a knife in the field is easier than ever with Quick Change Knives, helping you maintain the best cut quality.

Quicker Dry Down

Getting your hay crop dried down fast is important, especially if you have weather events looming. The John Deere S250, S300, S350, C300, C350 and C400 Mower-Conditioners give you the ability for wider windrows, thanks to the forming vanes. These wider windrows help the crop dry down faster, preserving the quality of the hay and giving you more time to bale before Mother Nature strikes.

Standing Behind our Durability

The 5-year cutterbar warranty shows how John Deere remains committed to the quality and durability of the John Deere Zero Series Mower-Conditioners. The proven drawbar swivel is now available on more models and provides increased maneuverability and driveline protection, letting you make tighter turns with increased peace of mind.

Cover More Ground with Mount Mower-Conditioners

Get a cutting width of more than 32 feet in one pass, with a narrow transport width of 10 feet. Choose from two front-mount and three rear-mount mower conditioners to meet your needs.

Technology & Tips

JDLink™ Connectivity

Enjoy all the benefits of a connected machine with a 4G JDLink MTG (modem), standard. Just activate the JDLink wireless service within your John Deere Operations Center account to start streaming machine and crop data to your account free of charge.

Tips Notebook

Visit our compilation of how-to tips, videos and ideas about how to get all kinds of jobs done around your place, including videos on hay mowing, tedding, raking, and bale handling.

Mower-Conditioner

• Easier serviceability with modular-design cutterbar
• Updated design and styling
• Reduce service time with Quick Change Knives
• Steel roll conditioners
• Impeller, urethane, V-10 conditioners or Tri-Lobe conditioners

Features may include:

Cutterbar flotation to match ground conditions

The front and rear mower utilize a hydropneumatic suspension system enabling them to follow ground contours. This simple system requires no springs to adjust the flotation system.

• Double-rod hydraulic cylinders are used to both lift the cutting platform and provide flotation.
• One side of the cylinders is linked to an accumulator to provide flotation.
• The other side of the cylinder is used for lifting the cutting platform for transport or going over headlands.
• Suspension system enables the cutting platform to follow ground contours at productive cutting speeds.
• Flotation is adjusted by opening a valve and using the tractor selective control valve (SCV) lever to alter pressure according to field profile. An easy-to-read gauge enables the operator to confirm that the pressure is within the recommended range. Ground pressure remains consistent even when cutting on uneven ground.

To improve driver comfort, hydraulic overlapping is available with +/- 20 cm (+/- 7.9 in.) if needed, actuated from the monitor in the cab. Ground contour following will be + 24 cm (+ 9.4 in.) upward and – 22.5 cm (- 8.9 in.) downward.

Ground clearance when raising the platform on headlands is approximately 40 cm (16 in.).

Cylinders work independently to enable the cutting platform to pivot from side to side to give clean cutting even on uneven ground. Angular range:

• + 13.3 degrees / - 8.1 degrees with 50 cm (19.7 in.) overlap.
• + 8.7 degrees / -4.1 degrees with 30 cm (11.8 in.) overlap.

On the R990M Twin Rear-Mounted, a hydraulic breakaway system is standard equipment:

• Should an obstacle be encountered, the cutting platform swings back and lifts up to pass over the obstacle.
• This reduces the potential damage to the cutting unit and decreases maintenance costs.
• For productivity and ease of use, the machine automatically resets on the go.

This flotation system ensures a perfect ground following, reducing soil compaction and providing an excellent cut. Crop stubble is preserved and regrowth is accelerated.

Simple monitor for easy operation of the rear mower's hydraulic functions

The simple monitor enables the operator to easily operate all of the hydraulic functions of the twin rear-mounted mower. The parts of the monitor include the following (arrows in the image above correspond to the alphanumeric values below):

1. Polarity inversion display light
2. On/off display light
3. On/off push button
4. Function selector 4:
   1. A — Front mower suspension adjustment
   2. B — Rear mower suspension adjustment
   3. 1 — Working/transport selection
   4. 2 — Right-hand or left-hand individual mower selection and headland selection
5. Push button for transport position
6. Three-way selector (left, center, or right)
7. Display lights

Rotary disk cutterbar for cutting in tough conditions

Power is transmitted from the 1000 rpm tractor with 44.4-mm (1-3/4-in.) power take-off (PTO) through a central gearcase to the twin rear-mounted cutterbars.

• Each cutterbar is protected by a slip clutch and overrunning clutch
• The cutterbar is securely mounted within the frame for strength and durability
• Power is transmitted to the rotary disks through fully enclosed gears, running in oil, for quiet, smooth, reliable operation
• The high-speed rotary disks cut in the toughest conditions. The disks rotate at 2986 rpm.
• Low-profile design enables cutting close to the ground at a flat angle helping prevent damage to the disks and knives
  • Cutting height is adjusted by changing cutting angle
• Pinion gear is easily removed from the top of the cutterbar for service
  • Idler gears can be removed from access area after removal of pinion gear

Groove on quill shaft, designed to shear upon severe impact with a foreign object, reduces the possibility of damage to the internal components of the cutterbar.

Quick-change knives technology

The cutterbar has been developed to increase productivity through a significant downtime reduction with quick-change knives.

The amount of time spent on changing knives went from 3 minutes per knife to about 15 seconds with quick-change knives. This resulted in saving up to 40 minutes of maintenance time on each platform.

The R990M is fitted with eight disks.

All operators have to do is insert the special tool (attached to the mower) between the disk and spring blade, push it down and remove the knife.

This results in no lost parts during the changing of knives.

Large farms, machinery rings, and contractors need high-quality output and ease of serviceability:

• Each disk is protected against heavy shocks with a shear point located on the disk drive.
• All modules and intermediate gears are quickly and easily interchangeable.

To meet high-quality output, the cutterbar is an oil-immersed gear-driven cutting bed:

• All disks are offering an orbital cutting diameter of 440 mm (17.3 in.)
• With seven disks, the cutting width will be 3.1 m (10.2 ft), and with 8 disks 3.5 m (11.5 ft)
• Disk speeds are 2986 rpm

To meet serviceability, the cutting bed is lubricated for life:

• No oil changes necessary
• Disks are fitted with quick-change knives technology
• Cutting height is from 35 to 85 mm (1.4 to 3.3 in.)

Time needed to change a knife is less than 15 seconds. It is an efficient way to win up to 30 minutes of maintenance time.

F350M and R990M Mower can easily be moved to transport or field position

The largest system is the R990M. This TMM system will have three 3.5 m (11.5 ft) mowers for a cutting width of 9.9 m (32.5 ft) per pass.

To prepare for transporting, the side curtains of the F350M Front-Mounted Mower are manually unlocked and folded into the transport position. This will reduce the overall width during transport. There is no longer a locking lever for the side curtains on the F350M mower. There is an additional locking mechanism for the front mowers to prevent the mower from swinging side to side in transport.

Once the front mower is in transport position, return to the cab of the tractor. To fold the rear mowers into the transport position, place dial indicator (4) in picture below on setting 1 and depress button 5 and tractor selective control valve (SCV).

The parts of the monitor include the following (arrows in the image above correspond to the alpha-numeric values below):

1. Polarity inversion display light
2. On/off display light
3. On/off push button
4. Function selector 4:
   1. A — Front mower suspension adjustment
   2. B — Rear mower suspension adjustment
   3. 1 — Working/transport selection
   4. 2 — Right-hand or left-hand individual mower selection and headland selection
5. Push button for transport position
6. Three-way selector (left, center, or right)
7. Display lights