M4 Overview

The Atrac M4 Cab Chassis is derived from the Goldacres G4 self-propelled model which forms the basis for a very versatile platform. This machine can be used for a wide range of accessories including spreader bodies or any other application that requires a high capacity, high clearance versatile tractor built to carry a load.

Built on a torsionally rigid semi truss fully welded chassis with 5 link suspension and heavy-duty torque rods, rear anti-sway bar and airbag suspension on all for corners to provide a stable, yet smooth ride.

Combine this with a full mechanical driveline to give uncompromising power, reliability and tractability to the ground.

  • 6.5 tonne carrying capacity

  • 1400mm clearance

  • Choice of tracks from 2-3

  • Choice of 2 or 4 wheel drive

Premium Cabin

Premium Cabin

Premium cabin is fitted with essential features and comforts to get you through the big days.

  • Easy to use fully moulded operator side console featuring all sprayer function control switches, drink holder & storage area.

  • Automatic transmission selector.
  • Grammer air ride seat with adjustable armrest and seat belt.
  • Fold away passenger seat.
  • Climate controlled air conditioner and heater with active carbon filtration. Ducted overhead storage box for drinks.
  • Curved front and rear glass, full-length side glass and large front windscreen wiper.
  • Engine monitor
  • Two-way tilt adjustable and telescopic steering column
  • Twin USB charge points plus 12v power take-off point for electronic accessories<
  • Pull down front blind
  • Accessory mounting rail.
  • Bluetooth AM/FM radio.
  • Stylish roof design with forward and rear facing lights (not shown)


Engine / Transmission

Cummins Tier 3 QSB 4.5L – 4 cylinder engine rated to 119kw (160hp) and 622N.m (459 lb-ft). Compact yet powerful.

Allison 2500 series 5 speed transmission. Overdrive reduces engine RPM whilst still maintaining 50 km/hr transport speed. Lock up clutches improve performance whilst dramatically reducing heat build up and fuel usage.

speed trans


  • Cummins Tier 3 QSB 4.5L – 4 cylinder engine rated to 119kw (160hp) and 622N.m (459 lb-ft). Compact yet powerful

  • Allison 2500 series 5-speed transmission. Overdrive reduces engine RPM whilst still maintaining 50km/hr transport speed. Lock up clutches improve performance whilst dramatically reducing heat build-up and fuel usage

  • Large vertically stacked cooling system for fuel, transmission, water jacket, charge air and air conditioning

  • Over the Radiator (OTR) air cleaner system with twin stage filtration provides cool clean air to the engine

  • Rear air lock differential** with inboard disc brakes

  • Oil filled final drive drop leg with planet hub reduction puts the power to the ground

  • Rear mounted exhaust system helps reduce in cabin noise


  • Trussing of chassis in the centre provides maximum strength with minimum weight
  • Integrated boom connection points. Non-flexing chassis provides a stable platform for boom control
  • Large capacity oil tank situated above the hydraulic pumps. Oil level visible from driver’s seat
  • 300L polyethylene fuel tank provides enough fuel for the longest spray days without the need to refuel

4WD System


The 4WD system utilises a single speed transfer case with front axle disconnect, allowing the sprayer to be used as a 2WD, helping to reduce fuel usage. At the flick of a switch, the front axle can be engaged, providing an equal power split between front and rear axles. If the going gets really tough, then the rear differential lock feature can also be engaged.

  • Two piece drive shaft transmission to transfer case

  • Oil cooled transfer case with front axle disconnect

  • Rubber isolator mounts to reduce vibration

  • Driven front axle with internal drive shafts and double carden universal joints allows tight turns

  • Rear axle differential with internal lock feature

  • Front & rear drop-leg 1:1 ratio chain drive planetary hub 5.33:1 ratio with oil bath lubrication

  • Transfer case to axle drive shafts

Wheel Track

Wheel Track

Wheel track width requirements can vary significantly depending on crop types and geographic regions.

There are 5 configurations of axles available in addition to wheels and tyres.

Track width
380/90 R46 tyres 480/80 R46 tyres
Fixed narrow track (2WD only) 2000mm 2100mm

Fixed wide track (2WD or 4WD*)

2870mm or 2970mm with offset rims 2970mm
Hydraulic adjustable narrow track on the move (2WD** only) 2000-3000mm 2100-3100mm
Manual adjustable wide track (2WD only) 2900-3900mm 3000-4000mm

Adjustable Wheel Track

Adjustable Wheel Track

An optional hydraulically adjustable axle providing a true 2000 to 3000mm wheel track is available.
Hydraulic track adjustment can be done on the move with a push of a button. Cylinders located inside the front and rear axles control the track width. Power is transferred to the rear wheels via multistage extendable drive shafts coupled to the droplegs to get the power to the ground.

No diff lock feature when this option is selected. Wheel track based on 380/40 R46 tyres, different width tyres may affect wheel track. Custom axle widths can be manufactured on request (2WD only).

Tight Turning

Tight Turning

The M4 Multi-trac has been designed to turn in very small headlands with the simplicity of a two-wheel steer configuration. The key in achieving this is the layout of the suspension system and open chassis design.

Axle type Tyre size Turning radius*
Hydraulic adjustable 2000-3000mm 380/80 R46 5000mm @2m^
4800mm @3m^
Fixed wide 2WD 3000mm 4800mm @3m^
4WD 3000mm 5800mm
Fixed narrow 2WD 2000mm 5800mm
Manual adjustable 3000-4000mm 4400mm @3m^
4200mm @4m^

M4 Dimensions

M4 Cab Chassis dimensions
Dimensions A (m) B (m) C (m) D (m) E (m)
M4 4.183 2.970* 7.231 3.82 1.476**

*3.5m when 480/80R46 tyres fitted at wheel track 2970mm
**Clearance with 480/80R46 tyres

M4 Specifications

Feature Description M4
Engine Cummins QSB 4.5L cylinder, Tier 3 emission. 119kw (160hp), 622N.m (459lb-ft) Standard
  Vertically stacked combi cooler package. Fuel, transmission, water jacket, charge air & air conditioning Standard
Transmission Allison 2500 series automatic. Mechanical selector, lock up torque converter, 5 forward & 1 reverse Standard
Drive system Differential with diff lock (non track width adjustable axles only). 3.33:1 ratio
5.3:1 ratio planet hub final drive leg with oil bath lubrication
  2 wheel drive Standard
  Full Mechanical Four Wheel Drive (4WD) using transfer box with fixed wheel track set to 2970mm Option
Steering 2 wheel front steering system with true Ackerman alignment* Standard
  Trimble platform hydraulic steering kit Option
  John Deere platform steering kit Option
Hydraulics 100L Plastic reservoir with level and temp gauge
Large oil cooler
Twin hydraulic circuits
Circuit 1 – 45cc/rev variable pump driven off PTO mount on Allison transmission. Max flow 112 l/min
Circuit 2 – twin-engine mounted gear pumps for combined displacement of 44cc/rev. Max flow 110 l/min
Electrical system LED front and rear mounted roof work lights Standard
  12V – 160amp electrical capacity
Dual batteries with master isolator mounted under engine
Fully sealed connectors with colour coded wires used throughout the wiring harness
  LED light bar Option
  LED service lights Standard
Braking system Air over hydraulic twin circuit boosted system Standard
  Transmission park brake Standard
  4 Wheel disc brakes Standard
Chassis Fully welded semi truss rigid mild steel
200 x 100 x 6mm main rails
Suspension 5 link torque rods with rear sway bar. 4 x rolling lobe air springs with ride height levelling. Shock absorbers on all corners, front feature double knuckle for extreme axle articulation Standard
Paint system Grit blasted steel work followed by high build primer. All unwelded sections seam sealed
Wet top coat paint system with high temperature baked finish
Wheel Equipment 460/85R38 front and rear Standard
  380/90R46 front & rear Option
  480/80R46 front & rear Option
Axle tracks 2970mm fixed wheel track Standard
  2000mm fixed wheel track Option
  2000-3000mm hydraulically adjustable track Option
Mudguards 4 x full length axle mounted polyethylene mudguards Standard
  4 x leading edge stainless steel crop deflectors Standard
Cabin Premium cabin with curved front and rear glass Standard
  Dual tilt and telescopic steering column Standard
  Air suspension seat with seat belt. Fully adjustable Standard
  Training seat Standard
  Accessory mounting rail on RHS Standard
  Carbon filtration with positive cab pressurisation Standard
  Bluetooth equipped radio Standard
  Engine and Transmission diagnostic display Standard
Main cabin access Full length LHS access platform with auto folding ladder. Standard
Fuel Tank Capacity  300L Poly diesel fuel tank Standard
Maximum Load Capacity 6,500 (kg) Standard
Weight Tare weight** (kg) 7,500

** Weights approx and vary according to options.

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