• 37,346 lb lbs Operating Weight
  • 218 @2100 rpm Horsepower
  • 14' Moldboard


With the longest wheel base in its class, the new GD655-6 offers exceptional fine grading performance.  Even with a long wheelbase, the GD655-6 maintains a tight minimum turning radius, thanks to a maximum articulation angle of 25 degrees.  This grader is extremely maneuverable and productive in tight road work or cul-de-sac applications.

Thanks to the new, Komatsu designed, Tier 4 Final power plant, GD655-6 owners should see a drop in fuel consumption of up to 5% when operating in “power” mode, and up to 15% in “economy” mode, compared to the GD655-5.

Komatsu’s Dual-mode transmission sets this grader apart from its competition.  The Dual-mode transmission has been specifically designed for use in Komatsu motor graders. It allows operators to benefit from the low-fuel consumption and high ground speeds of a direct-drive transmission, as well as the high tractive effort, superior control at low speed, and anti-stall features of a torque converter transmission.

GD655-6 Walkaround  >


Dual-mode Transmission

The dual-mode transmission is built specifically for Komatsu motor graders. The transmission provides full power shifting as well as inching capabilities and automatic shifting in the higher ranges.

Higher Productivity & Lower Fuel Consumption

A new variable displacement piston pump, improvements in the transmission and driveline components, and a sophisticated electronic control system for the engine and transmission all combine to achieve optimum and efficient operation. The new GD655-6 will consume up to 15% less fuel than the GD655-5.

Fuel consumption
up to 5% reduction
(P mode)
up to 15% reduction
(E mode)

(Compared with GD655-5)

Long Wheel base & Short Turning Radius

Longest wheelbase in class for exceptional fine grading performance. A 25 degree articulation angle allows the GD655-6 to maintain a tight turning radius of 24'3" making this grader very maneuverable for tight road work and cul-de-sac operation.

Tier 4 Final Engine

The Komatsu SAA6D107E-3 engine is EPA Tier 4 Final emissions certified and provides exceptional performance while reducing fuel consumption. Based on Komatsu proprietary technologies developed over many years, this new diesel engine reduces nitrogen oxides (NOx) compared to the previous model.

Excellent Visibility

Excellent visibility from the hexangular cab and layout of the rear side pillars boost operator confidence and productivity in all grader applications. Well-positioned blade linkage provides an unobstructed view of the moldboard and front tires.


Blade Range

Moldboard side shift:
Right 820 mm 2'8"
Left 820 mm 2'8"
Maximum shoulder reach outside rear tires (frame straight)
Right 2000 mm 6'7"
Left 2000 mm 6'7"
Maximum lift above ground 480 mm 1'7"
Maximum cutting depth 615 mm 2'0"
Maximum blade angle, right or left 90°
Blade tip angle 40° forward 5° backward


Service brake Foot operated, sealed oil disc brakes, hydraulically actuated on four tandem wheels.
Parking brake Manually actuated, spring applied, hydraulically released caliper.

Capacities (Refilling)

Fuel tank 390 ltr 103 u.s. gal
Cooling system 30 ltr 7.9 u.s. gal
Crank case 23 ltr 6.1 u.s. gal
Transmission 45 ltr 11.9 u.s. gal
Final drive 17 ltr 4.5 u.s. gal
Tandem housing (each) 57 lt 15.1 u.s. gal
Hydraulic system 69 ltr 18.2 u.s. gal
Circle reverse housing 7 ltr 1.8 u.s. gal


Single piece rolled ring forging. Six circle support shoes with replaceable wear surface. Circle teeth hardened on front 180° of circle.
Diameter (outside) 1530 mm 5'0"
Circle reversing control hydraulic rotation 360°


A-shaped, u-section press formed and welded construction for maximum strength with a replaceable drawbar ball.
Drawbar frame 210 x 22 mm 8.3" x 0.87"


Model SAA6D107E-3*
Type Water-cooled, 4-cycle, direct injection
Aspiration Turbocharged, aftercooled, cooled EGR
Number of cylinders 6
Bore 107 mm 4.21"
Stroke 124 mm 4.88"
Piston displacement 6.69 ltr 408 in3
Gross horsepower (Manual mode):
Gear 1-3 @2000 rpm 136 kW 183 HP
Gear 4-6 @2000 rpm 151 kW 203 HP
Gear 7-8 @2100 rpm 165 kW 221 HP
Gear 1-6 @2000 rpm 136 kW 183 HP
Gear 7-8 @2000 rpm 165 kW 221 HP
Net horsepower** (Manual mode):
Gear 1-3 @2000 rpm 134 kW 180 HP
Gear 4-6 @2000 rpm 149 kW 200 HP
Gear 7-8 @2100 rpm 163 kW 218 HP
Gear 1-6 @2000 rpm 134 kW 180 HP
Gear 7-8 @2000 rpm 163 kW 218 HP
Max. torque @1450 rpm 941 Nm 96.0 kg•m 694 lb.ft.
Torque rise 30 %
Fan speed Max. 1450 rpm
Air cleaner 2-stage, dry-type
* EPA Tier 4 Final emissions certified.
** Net horsepower output for standard (SAE J1349) including air cleaner, alternator (not charging), water pump, lubricating oil, fuel pump, muffler and fan running at minimum speed.


Front Frame Structure
Height 300 mm 11.8"
Width 300 mm 11.8"
Upper, Lower. 25 mm 1.0"

Front Axle

Type Solid bar construction welded steel sections
Ground clearance at pivot 620 mm 2'0"
Wheel lean angle, right or left 16°
Oscillation, total 32°

Hydraulic System

Load-sensing closed center hydraulics with variable displacement piston pump. Short stroke/low effort direct acting control valves with preselected maximum flow setting to each function. Double acting anti-drift check valves on blade lift, tip, circle shift, articulation, and leaning wheels.
Output (at engine rated rpm) 200 L/min 52.8 u.s.gal/min
Standby pressure 3.4 MPa 35 kg/cm2 500 psi
Maximum system pressure 20.6 MPa 210 kg/cm2 3,000 psi


Electric monitoring system with diagnostics:
Gauges / Standard: articulation, engine coolant temperature, fuel level, speed meter, transmission shift indicator, engine tachometer, torque converter oil temperature
Warning lights / Indicator: battery charge, brake oil pressure, blade float, brake oil pressure, inching temperature, directional indicator, engine oil pressure, hydraulic oil temperature, heater signal, lift arm lock, parking brake, differential lock, torque converter oil, temperature, ecology, P mode, fan reverse, rpm set, high beam, working lights


Hydraulic power shift fabricated from high tensile steel. Includes replaceable metal wear inserts, cutting edge and end bits. Cutting edge and end bits are hardened.
Dimensions 4320 x 660 x 22 mm 14' x 26" x 0.87"
Arc radius 432 mm 1'5"
Cutting edge 152 x 16 mm 6" x 0.63"
Replaceable/Reversible side edges 156 x 16 x 456 mm 6' x 0.63" x 1'6"
Blade pull:    
Base GVW 10100 kg 22,267 lbs
With ripper GVW 10980 kg 24,207 lbs
Blade down pressure:
Base GVW 6940 kg 15,300 lbs
With ripper GVW 8400 kg 18,519 lbs

Operating Weight (approximate)

Includes lubricants, coolant, full fuel tank
Total 16940 kg 37,346 lb
On rear wheels 12620 kg 27,822 lb
On front wheels 4320 kg 9,524 lb
With rear mounted ripper and front push plate:
Total 18900 kg 41,667 lb
On rear wheels 13820 kg 30,468 lb
On front wheels 5070 kg 11,177 lb
With mid-mounted scarifier:
Total 17480 kg 38,537 lb
On rear wheels 12600 kg 27,778 lb
On front wheels 4870 kg 10,737 lb

Rear Axle

Alloy steel, heat treated, full floating axle with lock/unlock differential




Ripping depth, maximum 425 mm 1'5"
Ripper shank holders 5
Ripper shank holder spacing 534 mm 1'9"
Penetration force 9390 kg 20,701 lbs
Pryout force 17600 kg 38,801 lbs
Machine length increase,beam raised 690 mm 2'5"


Middle, V-type:
Working width 1430 mm 4'8"
Scarifying depth, maximum 190 mm 7.5"
Scarifier shank holders 11
Scarifier shank holders spacing 138 mm 5.4"
Working width 2186 mm 7'2"
Scarifying depth, maximum 165 mm 6.5"
Scarifier shank holders 9
Scarifier shank holders spacing 267 mm 10.5"


Hydraulic power steering providing stopped engine steering meeting ISO 5010.
Minimum turning radius 7.4 m 24'3"
Maximum steering range, right or left 49°
Articulation, right or left 25°

Tandem Drive

Oscillating welded box section 520 mm x 202 mm 1'8" x 8"
Side wall thickness:
Inner 22 mm 0.87"
Outer 19 mm 0.75"
Wheel axle spacing 1525 mm 5'0"
Tandem oscillation 11° forward 13° reverse
Tank 7 L 1.8 U.S. gal

Transmissions and Torque Converter

Full power shift transmission with integral free wheeling stator torque converter and lock-up.
Speeds (at rated engine speed)
Gear Forward Reverse
1st 3.4 km/h
2.1 mph
4.5 km/h
2.8 mph
2nd 5.0 km/h
3.1 mph
9.2 km/h
5.7 mph
3rd 7.0 km/h
4.3 mph
20.3 km/h
12.6 mph
4th 10.2 km/h
6.3 mph
40.3 km/h
25.0 mph
5th 15.4 km/h
9.6 mph
6th 22.3 km
13.9 mph
7th 30.6 km/h
19.0 mph
8th 44.3 km/h
27.5 mph

Wheels, Front and Rear

Bearings Tapered roller
Tires 17.5R25
Tire rims (demountable) 13" one-piece rims


Engine and its related items:

  • Accelerator and electric throttle control
  • Air cleaner, double element with dust indicator
  • Air intake extension
  • Antifreeze -22 F(-30C)
  • Auto-idle Shutdown
  • Hydraulic driven, reversing, cooling fan, blower type, plastic blade, with fan guard
  • Engine, Komatsu SAA6D107E-3, 145 to 218 VHP EPA Tier 4 Final certified, turbocharged and air-air after cooled
  • Fuel line pre-filter
  • KDPF - After-Treatment Assembly Consisting of KDOC and KCSF
  • Secondary Engine Shutdown Switch
  • Selective Catalytic Reduction (SCR) System

Electrical system:

  • Alarm, backup
  • Alternator, 140 Ampere, (24V)
  • Batteries, Extreme duty, 2 x 12V, 1146 cca each
  • Battery, disconnect switch
  • Dome light cab
  • Headlights,(2) halogen type, front bar mounted
  • Horn, electric
  • Indicator lights:
    - Battery charge

    - Blade float

    - Brake oil pressure

    - Cooling fan reverse mod
    - Differential lock
    - Differential oil temperatur
    - Dual power mode, economy and power

    - Engine oil pressure

    - Engine RPM set

    - Lift arm lock

    - Lights, high beam

    - Parking break

    - Transmission system electrical circuit
  • Lights, backup, stop, directional
  • Starter 5.5kW
  • Working light, front(4) and rear(2)
  • Working light ,(4)cab mounted flood type

Operator environment:

  • 12V (10A) power port
  • Air conditioner (R134a) with heater
  • AM/FM radio
  • Cab: low profile with ROPS/FOPS Level II (SAE J1040, J2311)
  • Console, adjustable with instrument panel monitoring system
  • Electric defroster rear window
  • Mirrors: interior cab, right and left exterior mirrors
  • Electric defroster rear window
  • Mirrors: interior cab, right and left exterior mirrors
  • Multi-monitor with 7" LCD Display
  • Rearview Camera and Monitor
  • Sound suppression,74 Dba at operators ear with floor mat with tinted windows, front, rear and door intermittent wiper/washers

Power Train

  • Dual mode transmission (8F-4R) power shift direct drive and torque converter with auto shift
  • Axle, rear full floating, planetary type reduction
  • Service brakes, fully hydraulic wet disc
  • Parking brake, spring apply, hydraulic release dry disc
  • Differential, manual lock/unlock
  • Tires and rims: 17.5R25 radials on one-piece 13" rims (6)

Work Equipment and Hydraulics

  • Blade accumulators
  • Blade lift float, detent type, LH and RH
  • Circle, drawbar mounted, 360° rotation with blade lift and circle side shift with anti-drift check valves
  • Circle slip clutch
  • Greaseless circle wear plates
  • Hydraulic control valve, 10 valve section with control levers
  • Hydraulic system, closed center, load sensing
  • Steering, full hydraulic with tilt steering wheel plus leaning front wheels and frame articulation with anti-drift check valves

Other Standard Equipment

  • Komtrax - Level 5
  • Precleaner, Turbo II
  • Provision for Grade Control, TOPCON
  • Rear hitch
  • Ripper, provision for battery cover and engine side covers
  • Steps and handrails, right, left and rear
  • Toolbox with lock
  • Vandalism protection, lockable fuel tank, hydraulic tank


  • Moldboard:
    --3710 mm x 660 mm x 22 mm
    12' x 26" x 0.87" with replaceable end bits
    --152 mm x 16 mm
    6" x 0.63" throughhardened cutting edges  and 5/8" hardware
  • Pusher plate (for use with rear mounted ripper/scarifier assembly)
  • Rear-mounted ripper/scarifier assembly includes (3) shanks or (9) scarifier shanks can be inserted into the available slots
  • Mid-mounted scarifier assembly (includes 11 shanks and replaceable points)
  • Amber colored warning light
  • 610 mm 2' LH/RH moldboard extensions
  • Kit provision for a single function front attachment