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Off-Highway Trucks

Caterpillar builds Off-Highway Trucks specifically for work in mines, construction and quarries. Our Off-Highway Trucks are pass-matched with Cat Wheel Loaders and Hydraulic Excavators to speed cycle times and maximize productivity.

773E Off-Highway Truck

Time proven iron and modern technology combine to provide a highly productive, durable and reliable off-highway truck focused on our customers greatest need…lowest cost-per-ton.

Product Details

Operating Specifications

Nominal Payload Class (100%) 55.5 tonnes
Top Speed – Loaded 62.2 km/h
Body Capacity - Struck 26.6 m3
Steer Angle 31 Degrees
Turning Circle Clearance Diameter 25 m
Body Capacity – SAE 2:1 35.2 m3
Turning Diameter - Front 22 m
Raise Time 9.5 Seconds
Lower Time 12.5 Seconds


Engine Model Cat® 3412E
Rated Engine Speed 2000 RPM
Gross Power – SAE J1995 530 kW
Net Power – SAE J1349 501 kW
Net Power - Cat 501 kW
Flywheel Power 501 kW
Net Power – 80/1269/EEC 501 kW
Net Power – ISO 9249 501 kW
Net Power - DIN 70020 681 PS
Number of Cylinders 12
Torque Rise 40 %
Bore 137 mm
Stroke 152 mm
Displacement 27 L
Peak Torque 3434 N·m

Weights – Approximate

Target Gross Machine Operating Weight 99300 kg
Chassis Weight 30200 kg
Body Weight 9210 kg

Capacity – Dual Slope – 100% Fill Factor

Struck 26.6 m3
Heaped 2:1 (SAE) 35.2 m3
Heaped 3:1 32.4 m3
Heaped 1:1 43.3 m3

Weight Distributions – Approximate

Front Axle – Empty 47.3 %
Front Axle – Loaded 33.3 %
Rear Axle – Empty 52.7 %
Rear Axle – Loaded 66.7 %


Forward 1 9.9 km/h
Forward 2 13.9 km/h
Forward 3 18.8 km/h
Forward 4 25.2 km/h
Forward 5 34.1 km/h
Forward 6 45.9 km/h
Forward 7 62.2 km/h
Reverse 13.1 km/h

Final Drives

Differential Ratio 3.64:1
Planetary Ratio 4.8:1
Total Reduction Ratio 17.48:1


Brake Surface – Front 1395 cm2
Brake Surface – Rear 61269 cm2
Brake Standards ISO 3450: 1996

Service Refill Capacities

Fuel Tank 700 L
Cooling System 122 L
Differentials and Final Drives 155 L
Steering Tank 34 L
Steering System (Includes Tank) 60 L
Torque Converter / Brake / Hoist Hydraulic Tank 133 L
Brake / Hoist System (Includes Tank) 307 L
Torque Converter / Transmission System (Includes Sump) 72 L
Crankcase 68 L
Torque Converter/Transmission System 53 L

Body Hoists

Pump Flow – High Idle 491 L/min
Relief Valve Setting – Raise 17225 kPa
Relief Valve Setting – Lower 3445 kPa
Body Raise Time – High Idle 9.5 Seconds
Body Lower Time – Float 12.5 Seconds
Body Power Down – High Idle 17.51 Seconds


Effective Cylinder Stroke - Front 234 mm
Effective Cylinder Stroke - Rear 149 mm
Rear Axle Oscillation 8.1 Degrees

Approximate Weights – Dual Slope

Chassis 30200 kg
Body 9210 kg
Standard liner 3900 kg
Front axle - empty 47.3 %
Front axle - loaded 33.3 %
Rear axle - empty 52.7 %
Rear axle - loaded 66.7 %
Gross vehicle 99300 kg


Sound Standards Meets SAE J88 APR95


ROPS/FOPS Standards Standards Meets SAE J1040 May94 and ISO 3471:1997


Height - Top of ROPS 4000 mm
Overall Body Length 8535 mm
Inside Body Length 6400 mm
Overall Length 9120 mm
Wheelbase 4191 mm
Rear Axle to Tail 2782 mm
Ground Clearance 591 mm
Dump Clearance 676 mm
Loading Height – Empty 3773 mm
Inside Body Depth - Max 1805 mm
Overall Height – Body Raised 8787 mm
Operating Width 5076 mm
Centerline Front Tire Width 3275 mm
Engine Guard Clearance 667 mm
Overall Canopy Width 4398 mm
Outside Body Width 3910 mm
Inside Body Width 3658 mm
Front Canopy Height 4424 mm
Rear Axle Clearance 591 mm
Centerline Rear Dual Tire Width 2927 mm
Overall Tire Width 4457 mm


Turning Diameter Front Wheel Track 22 m
Turning Diameter – Front 22 m
Steering Standards Steering Standards Meets SAEJ1511 FEB94 and ISO 5010:1992
Steer Angle 31 Degrees
Turning Circle Clearance Diameter 25 m


Standard Tire 24.00-R35 (E4)

Operator Station

Control ease and comfort maximize productivity

Ergonomic Controls at the Operator's Fingertips

The ROPS/FOPS cabin has electric power window, electro-hydraulic hoist lever, trainer’s seat, front brake cut-off switch, backlit LED gear numbers, and optional heater and air conditioner. The hoist lever is electro-hydraulic and fingertip actuated, providing low impact body-down snubbing.

Electronic Monitoring System (EMS) - Critical Data in Three Separate Displays

(1) Four-gauge cluster - coolant temperature, oil temperature, brake air pressure, fuel level (2) Tachometer, digital speedometer, actual gear indicator (3) Message center module

Contour Series Air Suspension Seat and Tilt-Telescoping Steering Wheel

Standard and fully adjustable, including an adjustable right-hand armrest. Steering wheel's ergonomic grip improves comfort and control. Low effort steering system and foot-operated retarder reduce operator fatigue. Turn signal lever includes high beam actuator and electric windshield wiper controls.

Visibility in an Integral, Quiet ROPS/FOPS Cab

Exceptional all-around viewing area reduces fatigue and improves operator confidence and productivity. Cab is resiliently mounted and sound-suppressed for a quiet, protected work environment, and is radio-ready.

Truck Production Management System (TPMS) (Optional) Provides Payload and Cycle Time Data

  • Cat technology uses strut pressure sensors and on-board processors to determine payload weight.
  • Consistently accurate payloads improve efficiency by minimizing overloading and underloading.
  • On-board computer stores 1,400 cycles of payload weight, cycle times, distances and more.

Power Train - Engine

Cat 3412E Turbocharged engine with a HEUI™ fuel system

Cat 3412E Air-to-Air After Cooled Diesel Engine

The four stroke design uses long power strokes for complete fuel combustion and optimum efficiency. High displacement/low speed rating extends engine life and meets China Nonroad Stage II Emissions Standards.


1) Valve Rotators 2) Turbocharger 3) Stellite-Faced Valves 4) Steel-Backed, Copper-Bonded Bearings 5) Oil Cooler 6) Forged Crankshaft 7) Adjustment-Free, Fuel Injection Pumps 8) Hydraulic Injectors 9) Forged Steel Pistons 10) Full-length, Water-Cooled Cylinder Liners

40 Percent Torque Rise Means Faster Cycle Times

High lugging force during acceleration and less downshifting on grade or rough underfoot conditions. Also effectively matches gear shift points for maximum efficiency.

3412E Power and Reliability Features

  • High pressure injection
  • Full electronic control
  • Copper-bonded crankshaft bearings
  • Hardened crankshaft journals
  • Dry-type, radial seal air cleaners (primary, secondary elements, precleaner)

HEUI™ Delivers Excellent Fuel Control

Electronically monitors operator and machine inputs to optimize engine performance. Independently controls injection pressure, timing and duration over the engine operating range. Rate shaping technology modifies the heat release characteristics of the combustion process for significant decreases in sound and exhaust emission levels.

Electronic Control Module (ECM)

The ECM monitors key functions and logs critical indicators. The Electronic Technician can access this diagnostic information for easier maintenance and repair.

Power Train - Transmission

The Cat transmission gets the job done smoothly and quickly.

1) Lock-up Torque Converter Extends Transmission Life and Increases Operator Comfort

High rimpull and cushioned shifts with direct drive's efficiency and performance.
  • Engages at approximately 6.9 km/h (4.3 mph), delivering more power to the wheels
  • Quickly releases / re-engages during shifts, maintaining power wind-up

2) Cat Seven-Speed, Power Shift Transmission

A modulating pressure valve regulates clutch pressure to ease clutch engagement, reducing shock loads.
  • Patented rotating clutch pressure seals minimize drag losses and improve reliability
  • 35 percent gear splits between all gears match Cat engine design for optimum use of engine power with minimized shifting and torque converter use
  • Matched with the 3412E engine for constant power over a wide range of operating speeds.
  • Seven speeds forward, one reverse; second through seventh gears are direct drive
  • First gear has both torque converter drive and direct drive

3) Final Drives

Final drive and differential torque multiplication of 17.48:1 further reduces stress on the drive train.

Axles, Wheel and Rims

Full floating axles are shot-peened to relieve internal stresses and increase durability. Rolled splines also provide increased service life. Cast rear wheels and center-mount rims are mounted using studs and nuts for maximum reliability.

Engine/Power Train Integration

Combining engine control module (ECM) with the transmission controller

Integrating Systems Improves Performance

Electronic control of the engine and transmission improves efficiency, lowers operating costs and extends machine life.

Cat Data Link

Integrates machine computer systems:
  • Controlled Throttle Shifting regulates engine speed during shifts to reduce driveline stress, and deliver smoother shifts and longer component life.
  • Economy Shift Mode modifies engine maps for lower fuel consumption.
  • Directional Shift Management regulates engine speed during directional shifts to prevent damage.
  • Elevated Idle Neutral Coast Inhibitor helps prevent shifts to neutral at speeds above 6.5 km/h (4 mph).
  • Body-up Shift Inhibitor helps prevent transmission shifts above a preprogrammed gear without the body fully lowered.
  • Event Memory stores operational data for Electronic Technician access. Data includes:
- Shift histograms - Operator-induced events - Lock-up clutch counter - Machine/Transmission overspeed

Electronic Technician (Cat ET)

Accesses engine and transmission data stored by the Cat Data Link System, and displays the status of all engine parameters.

Cat Electronic Monitoring System (EMS)

Displays information on request, and alerts the operator to abnormal conditions with a three-category warning system.

Optional Attachments

  • Automatic Retarder Control (ARC) automatically controls retarding on grade, maintaining ±2,230 rpm.
  • Traction Control System (TCS) improves performance in poor underfoot conditions by electronically monitoring and controlling wheel slip.
  • Integrated Brake Controller (IBC) combines ARC and TCS, reducing electronic components and electrical lines.

Oil-Cooled, Rear Disc Brakes

Rear braking lets the operator concentrate on the haul road.


1) Parking/Secondary Piston, 2) Service/Retarding Piston, 3) Friction Discs, 4) Steel Plates, 5) Actuating Springs, 6) Cooling Oil In, 7) Cooling Oil Out

Multiple Disc Brakes - Exceptional, Fade-Resistant Braking and Retarding

Cat multiple disc brakes use continuous forced oil-cooling. The optional ARC and TCS utilize the oil-cooled rear brakes to enhance truck performance and increase productivity.

Oil-Cooled Rear Disc Brakes

Designed and built for reliable, adjustment-free operation providing superior performance and service life in comparison to shoe-type and dry-disc systems. The system combines service, retarding and parking brake functions in a single unit. If hydraulic system pressure drops below a certain level, the spring applied secondary piston automatically applies the brake.

Oil Film Prevents Direct Contact Between Discs

Absorbing the braking forces by shearing oil and carrying heat away, this design extends brake life.

Secondary Braking

Spring-applied, hydraulically released, oil-cooled disc brakes are located on the rear axle. The front brakes will activate as part of the secondary system, even if switched out of service.

Parking Brakes

Spring-applied, hydraulically released parking brakes use wet disc brakes in the service system. A toggle switch activates the parking brake.


A Caterpillar patented, two-piston design combines the service, secondary and parking brakes, along with retarding functions.

Integrated Braking Control (IBC)

Combines benefits of Automatic Retarding and Traction Control System

Automatic Retarder Control (Optional)

The ARC electronically controls braking on grade to maintain approximately 2,230 rpm (engine rpm is adjustable from 2,150-2,300 rpm in increments of 10 rpm). ARC is deactivated when the operator applies the brakes or throttle.

Engine Overspeed Protection

With the accelerator depressed and/or ARC turned off, ARC will automatically activate at 2,475 rpm to help avoid potentially destructive and often costly engine overspeeds.

Traction Control System (Optional)

Senses if rear wheel slip exceeds the set limit, and automatically applies rear brakes to slow the spinning wheel.

Operator Awareness

An on-dash indicator shows the operator that TCS is engaged.

Differential Action

Utilizes normal differential action to provide superior maneuvering in poor underfoot conditions. Also reduces tire scuffing as compared to positive lock differentials used on other systems.


TCS divides torque equally to reduce stress created on final drives and axles when torque is transferred to one side.

System Back-up

Should sensors fail, the normal differential action is still available to maintain control and steering.

Truck Body

Rugged body for varying applications

Designed To Handle a Variety of Material Densities.

Maximum payload in 3-5 passes with matched Cat loader in material over 1700 kg/m³ (2,900 lb/yd³).

Truck Body Features

  • Sidewall and floor junctions use five-sided beams to resist impact loads and hauling stresses
  • Box-section beams increase durability in the floor, sidewalls, top rail, corner and cab canopy areas
  • 400 Brinell Steel wear surfaces provide excellent wear resistance and are easily cold welded
  • Two-stage hoist cylinders raise in 9.5 seconds, lower in 12.5 seconds
  • Standard Body comes exhaust heated with options including a full-time muffler or exhaust diverter
  • Custom attachments include tail end liner, sideboards and more, to help ensure rated payload.

Dual-Slope Body Delivers Lowest Cost-Per-Ton

Efficient in most construction and mining applications, but excels on rough haul roads and steeper grades.

Body Floor Construction

  • 8° "V" Bottom - Centers loads, lowers the center of gravity, increases retention, reduces shock loads
  • 18° Ducktail and 9° Forward Body Slope - retains loads on 15% grade
  • 12° Single Slope - Excellent wear characteristics and uniform dumping into hoppers, crushers and feeders.


The backbone of the Cat off-highway truck

Box-Section Design

The 773E frame uses 20 castings in high stress areas with deep penetrating and continuous wrap-around welding. Mild steel provides flexibility, durability and resistance to impact loads even in cold climates.

Rollover Protection Structure (ROPS)

The ROPS attaches securely to four castings welded into the frame.

Frame Features Include:

  • Integral front bumper and front box beams for suspension cylinder and ROPS suppor
  • Box-section rear crossmember for body and ROPS support with attachment points for maintenance platform and rear engine hood hinge suppor
  • Castings provide additional strength in critical stress area
  • Mild steel plates (290 MPa [42,000 psi] minimum yield strength) and castings (241 MPa [35,000 psi] minimum yield strength) provide flexibility, durability and easy field maintenance
  • Castings provide additional strength in critical stress areas

Box-Section Frame Simplifies Access to Power Train Components

Open design reduces overall removal and installation time, lowering repair costs. Repairs can be made without preheating in ambient temperatures above 16° C (60° F) using readily available welding supplies.

Suspension System Dissipates Haul Road and Loading Impacts

Four independent suspension cylinders absorb shocks. Rear cylinders allow axle oscillation and absorb bending and twisting stresses. Front cylinders act as steering kingpins, for maneuverability and reduced maintenance.

Serviceability/Customer Support

Cat Dealers offer their total commitment to customer support.

Improved Serviceability and Machine Availability

Allows 30-50% faster engine service (changing most oil and filters). Improves service scheduling, allows servicing during normal work hours and reduces total engine service time.

Machine Platform

The machine platform provides access to the air tanks, brake master cylinder and make-up tank; engine oil level; air filters; steering hydraulic tanks; and battery compartment.

Ground Level Battery Disconnect

On-Board Diagnostics

Off-Board Diagnostics

Radial Seal Filters

Easy to change, radial seal filters reduce air filter maintenance times.

Vertical, Spin-On Filters

Simplified servicing and the elimination of spillage are benefits of vertical, spin-on filters.

Quick Coupler Pressure Taps

Sealed Electrical Connectors

Machine Management Service

Cat dealers help manage equipment investments with:
  • Vehicle systems analysis to help match the right machine to the job
  • Preventative maintenance programs
  • S•O•S oil analysis and technical analysis programs
  • Repair option analysis
  • Training for operators and mechanics
  • TPMS data analysis

Parts Availability

The Caterpillar worldwide computer network locates parts instantly to minimize machine downtime.

Literature Support

Systems / Applications

The 773E is designed for versatility.

Machine Configuration Options

Tire Options


System Approach

Cat Product Analysis Team (PAT)

Loader Match

  • Air cleaners, dry-type, radial seal, primary and secondary elements
    • Air horn, electric
      • Air line dryer
        • Alternator, 50-amp
          • Auxiliary jump start receptacle
            • Backup alarm
              • Batteries, 12V (2), low maintenance
                • Battery disconnect switch, ground level
                  • Body mounting group
                    • Brakes -
                      •  Caliper disc (front)
                      •  Oil disc (rear)
                      •  Parking
                      •  Secondary
                    • Brake (front) disconnect switch
                      • Brake heat exchanger
                        • Brake release motor, for towing
                          • Cab, ROPS -
                            •  Cat Contour Series air suspension seat
                            •  Coat hook
                            •  Cup holder
                            •  Insulated and sound-suppressed
                            •  Radio ready
                            •  Storage compartment
                            •  Sun visor
                            •  Tinted glass
                          • Crankcase guard
                            • Diagnostic connection port, 24-volt
                              • Drive line guard
                                • Electrical system, 24-volt
                                  • Electronic Monitoring System
                                    • Filters, spin-on
                                      • Gauges -
                                        •  Actual Gear Indicator
                                        •  Air pressure
                                        •  Brake oil temperature
                                        •  Coolant temperature
                                        •  Fuel
                                        •  Hour meter, electric
                                        •  Odometer
                                        •  Speedometer
                                        •  Tachometer
                                      • Actual Gear Indicator
                                        • Air pressure
                                          • Brake oil temperature
                                            • Coolant temperature
                                              • Fuel
                                                • Hour meter, electric
                                                  • Odometer
                                                    • Speedometer
                                                      • Tachometer
                                                        • Hoist lever, fingertip-actuated
                                                          • Lighting system -
                                                            •  Backup light
                                                            •  Dome/courtesy light
                                                            •  Hazard and directional signals, LED
                                                            •  Headlights, halogen, with dimmer
                                                            •  Stop/tail lights, LED
                                                          • Backup light
                                                            • Dome/courtesy light
                                                              • Hazard and directional signals, LED
                                                                • Headlights, halogen, with dimmer
                                                                  • Stop/tail lights, LED
                                                                    • Mirrors, right and left
                                                                      • Power port, 24-volt
                                                                        • Precleaner
                                                                          • Reservoirs (separate) -
                                                                            •  Brake/hoist
                                                                            •  Steering
                                                                            •  Transmission/torque converter
                                                                          • Retarder
                                                                            • Rock ejectors
                                                                              • Seatbelts, retractable
                                                                                • Seat, passenger
                                                                                  • Service platform, bolt-on
                                                                                    • Starting, electric
                                                                                      • Steering, automatic supplemental, electric
                                                                                        • Steering wheel, padded, tilt, telescopic
                                                                                          • Tires, 24.00-35, radial
                                                                                            • Tow hooks, front
                                                                                              • Tow pin, rear
                                                                                                • Transmission -
                                                                                                  •  electronically controlled automatic power shift with downshift/reverse shift inhibitor, neutralizer during dumping, neutral start switch, engine overspeed protection, directional shift management, programmable top gear, body-up shift limiter, economy shift
                                                                                                • Vandalism protection locks
                                                                                                  • Window, electric power (operator)
                                                                                                    • Windshield wipers and washer, electric intermittent
                                                                                                      • Air conditioning
                                                                                                        • Automatic lube system
                                                                                                          • Automatic Retarder Control (ARC)
                                                                                                            • Body side boards
                                                                                                              • Body Tail end Liner
                                                                                                                • Clustered grease fittings
                                                                                                                  • Dual slope body
                                                                                                                    • Engine coolant heater - 120 volt
                                                                                                                      • Engine coolant heater - 240 volt
                                                                                                                        • Exhaust diverter/muffler
                                                                                                                          • Extended life brake
                                                                                                                            • Fuel heater kit
                                                                                                                              • Integrated brake control
                                                                                                                                • Muffler
                                                                                                                                  • Spare rim 432 mm (17")
                                                                                                                                    • Traction Control System (TCS)
                                                                                                                                      • Truck Production Management System (TPMS)
                                                                                                                                        • Wheel chocks
                                                                                                                                          • Wiggins fast fuel change
                                                                                                                                            • Wiggins high-speed oil change
                                                                                                                                              Built for it