• 366,000 lbs Max Gross Vehicle Weight
  • 1,200 @1900 rpm Gross HP
  • 100.3 U.S. tons Capacity


If you are looking for a truck that perfectly matches power, speed and reliability, the 100 ton capacity HD785-7 is the truck for you. Your operator can max his production by using his two working modes, tight turning radius, hydropneumatic suspension, skip shift function and oil multi-disc brakes and retarder. And he’ll do it in comfort in an ergonomic cab that rides on viscous dampers that reduce vibration and sound. Downshift, over-run and reverse inhibitors protect the truck and give the operator peace of mind.


Variable Horsepower Control

Both in Power and Economy modes, the VHPC system detects whether the truck is loaded or not loaded and selects the optimum horsepower setting mode, providing both high production and low fuel consumption.

Power mode

Makes the best use of horsepower to attain optimal production. This mode is suitable for operation in job sites including uphill travel with a load where throughput takes top priority.

Economy mode

Sets the maximum horsepower at a lower level to reduce fuel consumption. The machine maintains sufficient power for normal operation in this mode.

Fully Automatic Transmission

The transmission is configured with 7 forward and 2 reverse gears. Fully automatic control is applied to all forward gears and an optimum gear is automatically selected according to the travel speed and engine speed. To reduce fuel consumption, the shifting point is automatically selected depending on the acceleration of the machine.


The HD785-7 is equipped with AP-FOUR that applies retarding force on all four wheels. This reduces the possibility of tire-lock and enables effective use of retarder capacity, allowing stable downhill travel. The machine descends slopes smoothly and comfortably without machine body pitching since retarding force on the front and rear wheels is controlled independently.
• Retarder Absorbing Capacity: 1092 kW 1,464 HP (continuous descent)
• Brake Surface Area (rear):
Front total: 37467 cm² 5,807 in²
Rear total: 72414 cm² 11,224 in²

Auto Retard Speed Control

ARSC allows the operator to simply set the downhill travel speed and go down slopes at a constant speed. This allows the operator to concentrate on steering. The speed can be set at increments of 1 km/h 0.6 MPH per click (±5 km/h 3.1 MPH of setting speed adjustment) to match the optimum speed for the slope. The retarder cooling oil temperature is constantly monitored and the descent speed is automatically reduced, if necessary.

Ideal Driving Position Settings

The 5-way adjustable operator seat and the tilt-telescopic steering column provide an optimum driving posture for increased driving comfort and more control over machine operation. The suspension seat dampens vibrations transmitted from the machine and reduces operator fatigue. A 78 mm 3" wide seat belt is provided as standard equipment.

Advanced K-ATOMiCS

The electronically controlled all clutch modulation system, “K-ATOMiCS”, optimizes the clutch engagement oil pressure at every gear. This system optimizes the clutch lock-up process for smoother shifting with minimal torque shock.

The Macpherson Strut-Type Front Suspension

The MacPherson-type independent suspension is utilized on the front wheels. This linkage arrangement allows the front wheel to follow the undulation of the road surface smoothly, realizing excellent riding comfort.

High-Rigidity Frame

Front support is integrated with the frame. The frame rigidity has been substantially increased. As a result, flexural rigidity and torsional rigidity, which are indicators of drivability and ride quality, are significantly improved.

Advanced monitoring system

The Komatsu advanced monitoring system identifies maintenance items, reduces diagnostic times, indicates oil and filter replacement hours and displays abnormality codes. This monitor system helps to maximize machine production time.



Rear axles Full-floating
Final drive type Planetary gear
Differential 3.357
Planetary 6.333


Struck 52.3 yd³ 40 m³
Heaped (2:1, SAE) 78.5 yd³ 60 m³
Payload 100.3 U.S. tons 91.0 metric tons
Material 400 Brinell hardness high tensile strength steel
Structure V-shape body with V-bottom
Material thickness:
Bottom 0.75" 19 mm
Front 0.47" 12 mm
Sides 0.35" 9 mm
Target area (inside length x width) 23'2"x 17'1" 7065 mm x 5200 mm
Dumping angle 48°
Height at full dump 33'1" 10080 mm
Heating Exhaust heating


Brakes meet ISO 3450 standard.

Service brakes:
Front Fully hydraulic control, oil-cooled multiple-disc type
Rear Fully hydraulic control, oil-cooled multiple-disc type
Parking brake Spring applied, multiple-disc type(actuates on all wheels)
Retarder Oil-cooled, multiple-disc front and rear brakes act as retarder
Secondary brake Manual pedal operation. When hydraulic pressure drops below the rated level, parking brake is automatically actuated.
Brake surface
Front 5,807 in² 37467 cm²
Rear 11,224 in² 72414 cm²


Integral four-post ROPS/FOPS Level 2 cab structure


Model Komatsu SAA12V140E-3
Type Water-cooled, 4-cycle
Aspiration Turbo-charged, after-cooled
Number of cylinders 12
Bore x Stroke 5.51" x 6.50" 140 mm x 165 mm
Piston displacement 1,860 in³ 30.48 ltr
SAE J1995 Gross 1,200 HP Gross 895 kW
ISO 9249 / SAE J1349 Net 1,178 HP Net 879 kW
Rated rpm 1,900 rpm
Fan drive type. Mechanical
Maximum torque 3,747 lb ft 518 kg•m
Fuel system Direct injection
Governor Electronic control
Lubrication system
Method Gear pump, force-lubrication
Filter Full-flow type
Air cleaner Dry type with double elements and pre-cleaned, with dust indicator

Hydraulic System

Hoist cylinder Twin, 2-stage telescopic type
Relief pressure 2,990 psi 20.6 MPa / 210 kg/cm²
Hoist time
Raise 13 sec
Lower 14 sec

Main Frame

Type Box-sectioned structure Integral front bumper

Service Refill Capacities

Fuel tank 345.6 U.S. Gal 1308 ltr.
Engine oil 34.1 U.S. Gal 129 ltr.
Torque converter, transmission and retarder cooling 54.2 U.S. Gal 205 ltr.
Differentials 36.2 U.S. Gal 137 ltr.
Final drives (total) 33.8 U.S. Gal 128 ltr.
Hydraulic system 46.2 U.S. Gal 175 ltr.
Brake control 9.5 U.S. Gal 36 ltr.
Suspension (total) 24.6 U.S. Gal 93 ltr.
Engine coolant 74.8 U.S. Gal 283 ltr

Steering System

Type Fully hydraulic power steering with two double-acting cylinders
Supplementary steering Electro-hydraulic motor
Minimum turning radius 33'2" 10.1 m
Maximum steering angle 41°

Suspension System

Independent, hydropneumatic suspension cylinder with fixed throttle to dampen vibration.

Effective cylinder stroke:

Front suspension 12.6" 320 mm
Rear suspension 5.0" 127 mm
Rear axle oscillation



Standard tire 27.00 R49


Torque converter 3-elements, 1-stage, 2-phase
Transmission Full-automatic, planetary-shaft type
Speed range 7 speeds forward and 2 reverse (RH, RL)
Lockup clutch. Wet, multiple-disc clutch
Forward Torque converter drive in 1st gear, direct drive in 1st lockup and all higher gears
Reverse Torque converter drive, direct drive (lockup)
Shift control Electronic shift control with automatic clutch modulation in all gear
Maximum travel speed 40.4 mph 65 km/h

Weight (approximate)

Empty weight 158,800 lb 72000 kg
Max. gross vehicle weight 366,000 lb 166000 kg
Not to exceed max. gross vehicle weight, including options, fuel and payload.
Weight distribution (Empty):
Front axle 47%
Rear axle 53%
Weight distribution (Loaded):
Front axle 31.5%
Rear axle 68.5%



  • Automatic Idling Setting System (AISS)
  • Alternator, 90A/24V
  • Batteries, 4 x 12V/170Ah
  • Engine pre-lube system 
  • Komatsu SAA12V140E-3 engine meets EPA Tier 2 emissions regulations
  • Mode selection system with VHPC
  • Starting motor, 2 x 7.5 kW 


  • Air conditioner
  • Ashtray
  • Cigarette lighter
  • Cup holder
  • Electronic dump control system with body positioner
  • Electronic maintenance display/monitoring system
  • Glass, tempered, sides and back
  • Heater and defroster
  • Integral ROPS/FOPS Cab Level 2
  • Laminated glass, front
  • Operator seat, reclining, air suspension type with retractable 78 mm / 3" width seat belt
  • Passenger seat with retractable 78 mm / 3" width seat belt
  • Power windows (LH & RH)
  • Radio, AM/FM with cassette
  • Space for lunch box
  • Steering wheel, tilt and telescopic
  • Sun visor (2)
  • Two doors, left and right
  • Windshield washer and wiper (with intermittent feature)


  • Back-up light
  • Hazard lights
  • Headlights
  • Indicator, stop and tail lights (LED type)


  • Exhaust thermal covers


  • Alarm, backup
  • Anti-pitching 4-wheel oil-cooled multiple disc retarder (AP-FOUR)
  • Automatic Retard Speed Control (ARSC)
  • Automatic supplementary steering
  • Coolant temperature alarm and light
  • Exhaust retarder
  • Guardrails for platform
  • Horn, electric
  • Overrun warning system
  • Rearview mirrors and underview mirrors (left & right side)
  • Rear view camera and monitor
  • Tire stopper blocks


  • Body exhaust heating
  • Cab guard, left side
  • Platform guard, right hand side
  • Spill guard, 150 mm / 6"


  • Centralized greasing
  • Diagonal stairway
  • Disc wheels (Flange type rims)
  • Drive shaft guard (front and rear)
  • Electric circuit breaker, 24V
  • Engine underguard
  • Fire extinguisher
  • Fuel quick charge
  • Komtrax Plus
  • Ladder, right hand side
  • Mud guards
  • Payload meter
  • Spare parts for first service
  • Transmission underguard
  • Vandalism protection



  • Body liners


  • Fog lights
  • HID side working lights


  • 27.00 R49


  • Antilock Brake System (ABS)
  • Automatic Spin Regulator (ASR) 


  • Batteries for cold area arrangement
  • Cold area arrangement, -30°C
  • Hot area arrangement, 50°C


  • Engine coolant heater
  • Engine oil pan heater
  • Engine side covers
  • Ground level coolant fast fill
  • Ground level oil fast fill
  • Mufflers, deck mounted
  • Three-mode hydropneumatic suspension