Caterpillar’s 777G: A new era for off-highway trucks

777G caterpillar off-highway truck

Building on a more than four-decade legacy of off-highway trucks, Caterpillar has announced the new 777G.

The new Cat 777G has a rated payload of 89.4 tonnes, with a standard-body volume of 64.1 cubic metres.

The design of the 777G, which replaces the 777F, focuses on fuel efficiency, enhanced visibility, as well as operator comfort, convenience and safety.

The new 777G’s Cat C32 ACERT engine meets US EPA Tier 4 Final and EU Stage V emission standards. The engine delivers 1,025 hp and incorporates a number of fuel-conservation features.

Auto Neutral Idle allows the 777G transmission to intermittently shift to neutral when the truck is idling in a forward gear to avoid stalling the torque converter and increasing engine speed.

Engine Idle Shutdown, an operator-selected feature, stops the engine when the truck idles in park for more than a preset interval. As well, Speed Limiting provides an alternative to gear-limiting by allowing the truck to travel at a more fuel-efficient engine speed and in a more efficient transmission gear.

Advanced Productivity Electronic Control Strategy (APECS) transmission controls boost fuel efficiency by maintaining momentum and speed on uphill grades during shifts.

Two operating modes

The 777G has two operating modes, Standard Economy and Adaptive Economy. Standard Economy saves fuel by reducing engine power by up to 15 per cent, based on the fleet and economic conditions at a particular site.

Adaptive Economy requires a production baseline for the site using the Advisor display, and then, as the truck travels the haul cycle, the system automatically evaluates the power rating needed to meet baseline requirements. Full power is applied when needed, and reduced power is applied when appropriate. The efficiency of the 777G’s performance is further enhanced by 7 per cent more engine torque and an increase in top speed.

The 777G’s redesigned cab

The 777G features a redesigned cab that is easier to enter and exit, and is equipped with a new operator seat and a more comfortable trainer seat on the right. A new console with an integrated hoist-and-shift lever enhances convenience, as does more interior space for storage.


The truck’s design also emphasizes improved visibility, to both the work area and instrumentation, and overall visibility is enhanced with an optional object-detection system.

Convenience items include a powered left window, automatic temperature control, throttle lock for long uphill grades and reduced interior sound by 50 per cent, compared with previous models.

Operator safety is a primary design factor for the 777G, with roll-over and falling-object protective structures integrated into the cab’s design. Laminated glass is used in the front and left windows, while emergency egress is provided via a right-side hinged window.

A ground-level engine-shutdown switch is readily accessible, and a secondary steering system is provided in the event of the primary steering system failure.

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Wet-disc brakes are used at all four corners and provide parking brake and slope-holding capability. Brake life can be extended with an available engine brake, and a brake-wear indicator assists with maintenance. Furthermore, automatic retarding adds to positive control on downhill grades, and a new steering-sensitive traction-control system assists when ground conditions deteriorate.

777G structures

The 777G’s major structures are designed for long-term durability in harsh operating conditions, engineered to endure through more than one power-train life cycle.

Box-section castings are used strategically in high-stress areas, a new front frame design increases the approach angle on ramps and grades, and a heavy-duty rear axle housing axle allows increased lubrication and filtration of critical components.

The Dual slope body, designed for material retention on haul roads with steep slopes, carries material low and centered for stability. Heaped capacity is 60.2 cubic metres in its standard configuration. As well, two side-board sizes increase capacity for lighter weight materials.

The X body has a flat floor and facilitates metering material into a crusher, while standard heaped capacity is 64.1 cubic metres. Light-material bodies provide capacities to 126 cubic metres.


Tire life can be extended for the 777G with the TKPH/TMPH feature that calculates tire loading, and a mud-protection package is available to help keep powertrain components clean.

The hydraulic-oil filter life is 1,000 hours under normal conditions. Fluid-fill and extraction points are grouped for convenience, and all check points are located at ground level and lighted for night access. A master disconnect switch, engine lock-out switch and hydraulic lockout switch provide a convenient method when servicing the 777G.