Mk3 Universal Cultivator with Hydraulic Tynes20L Gas Accumulator - Protects from hydraulic pressure overload

Mk3 Seeder Bar

Following many years of success in the field, John Shearer have released a new model of our popular 5 row Universal Cultivator.

Major changes include, a revised main frame and wings, reengineered wing fold and a completely new hydraulic tyne assembly. The new low profile frame allows the fitting of John Shearer hydraulic tynes or Double Disc Opener assemblies for maximum flexibility.

Watch our videos for a testimonial and to see the Mk3 Seeder Bar in action:


  • New low profile 100mmx100mm main frame
  • Available with either, hydraulic tyne assemblies or double disc parallelogram openers
  • Optional “in cab” digital tyne breakout pressure gauge
  • New folding configuration; four individual cylinders
  • Sowing spacings, from 200mm (8”), Double disc openers from 254mm (10”)
  • Revised hydraulic loading system
  • New 800H hydraulic tyne assembly
  • Narrow & standard centre models are available

Main Frame

The main frame includes 5 row (5) 100mm x 100mm mounting ranks, of which front and rear centre section beams are 9mm for additional strength. The new “low profile” design frame allows easier fitment of air kits and other bolt–on accessories.

Hydraulic Loading

Larger models are standard with a 20 litre gas accumulator. This provides protection from pressure overload during working. ‘In-line’ valves, fitted to the hydraulic circuitry, assist in controlling the recoil speed and force of the tynes as they return to the work position. A digital tyne breakout pressure gauge, fitted in the tractor cab, is an option.


Hydraulic Tyne & Opener Options:

New 800H Tyne Assembly

The new re-engineered tyne assembly is easier to fit and does not add unnecessary additional weight to the machine. Also, servicing of the cylinder is a much simpler operation. The downward pressure can be adjusted to more than 205 kgs (450 lbs) and the tyne has an extra large underframe clearance of 800mm (31.5”). The assembly has the facility for locking tynes in the raised position, which is ideal when sowing on alternate rows. The tyne foot has two 1/2” bolts at 1 3/4” centres, which accepts a wide range of ground engaging tools.

Double Disc Opener – Unique Design

The John Shearer double disc opener’s compact and unique design, places the press wheel much closer to the sowing boot than most others on the market. The opener is a true parallelogram unit and is based around two (2) carriers. The mounting carrier attaches the unit to the frame, while the main carrier has the ground engaging coulters, (or optional tyne) and press wheel attached. The parallelogram design, allows the openers to closely follow ground contours, giving a more uniform seed placement.

The opener has, 15” coulter & press wheel, 254mm (10”) of vertical ground following capability and features a spring return mechanism for transport.

Wing Fold System

Four 4”x30” folding cylinders are standard equipment – one on each hinge point.

Simple Leveling Adjustment

Two double acting lift cylinders fitted to the centre section are mechanically linked to the wings. There are no phasing cylinders. To level the machine front to rear, the castor linkages are adjusted and for ‘across the width’ levelling, the inner layshaft links control the centre to the wings.


Working Widths for standard centre 8.9m (29’5”), 10.8m (35’6”), 12.6m (41’ 6”)
Number of Tynes @ 10″ Interval 8.9m: 35, 10.8m: 43, 12.6m: 51
Tyne Extensions Optional 2 & 6 tyne extensions
Transport Width Standard centre: 7.1m,
Narrow centre: 6.1m
Hitch Fully Floating 5.2m (17′)
Sowing Spacing Tyne model: From 200mm (8″),
Disc Opener model: From 254mm (10″)
Number of Rows Five (5) mounting beams
Spacing Between Rows 1 & 2: 705mm, 2 & 3 765mm, 3 & 4: 765mm, 4 & 5: 765mm
Underframe 800mm (31 1/2″)
Wheel Centres Standard centre: 4.0m,
Narrow centre: 3.0m
Jumper Hydraulic Circuit Larger sizes – 20 Litre Gas Accumulator
Tyne Breakout Adjustable to more than 205 kgs (450lbs)
Tyne Jump Height 515mm (20.3″)
Depth Control Rockshaft w/- tandem cylinders, mechanically linked to wing wheels
Working Depth Tyne (max.): 180mm (7″)
Wing Fold Two pairs of 4” x 30” cylinders
Centre Wheels 16/70 x 20 x 14 ply lug
Castor/Wing Wheels 12.5/80 – 15.3 x 14 ply

Download Product Brochure PDF

Due to our policy of continuing research, specifications are subject to change without prior notice.