Caterpillar optimizes engine performance while meeting U.S. EPA Tier 3 and European Union Stage IIIa engine emission regulations. ACERT Technology reduces emissions during the combustion process by using advanced technology in the air and fuel systems, in conjunction with integrated electronics. Caterpillar meets emission regulations at the combustion source, rather than recycling exhaust gases.

The C15 block incorporates a one-piece, grey iron block, featuring generous ribbing for stiffness and heavy bearing bulkheads for rigidity and strength. Caterpillar also has moved away from pipe thread ports to straight-thread, o-ring connection points, reducing the potential for leaks. This new design supports the engines higher compression ratios and increased power density.

The new cross flow air design routes air straight across the head removing bends and turns that create resistance to flow. By removing the resistance to flow, parasitic loads are reduced as pumping needs are lessened. The cylinder head is a one piece, cast iron component with a newly designed graphite and steel composite head gasket that seals the combustion chamber with better rigidity and wear capability.

A single overhead cam is driven by gears on the front of the engine, which significantly reduce noise and vibration. Caterpillar also has added two pendulum absorbers, mounted at the front of the camshafts to further reduce noise and vibration.

New design and material improvements to the pistons, rods and liners have been made to support the higher cylinder pressures and the 18:1 compression ratios associated with ACERT Technology, while still providing durability to engine overhaul. A single-piece steel piston, pulsator-tested to 4,000 psi, is matched to a robust connecting rod to ensure long component life. The pistons steel skirt increases its durability and results in reduced thermal expansion, allowing a tighter piston fit and reduced liner vibration. The overall piston surface area reduces friction and enhances fuel economy. The newly designed connecting rod allows better lubrication and cooling and is more securely fastened to the crankshaft using two additional bolts. The new improved rod bearings are made of steel-backed copper alloy with lead tin overlay. This new metallurgy reduces flaking and offers better fatigue strength. Cylinder liners are wet liners made of compacted graphite and iron for excellent wear and strength characteristics. Also, the tolerances between the pistons and the wet cylinder liners have been tightened to unprecedented levels for reduced blow-by and higher efficiency.

The single, waste-gated turbocharger found on the C15 engine is water-cooled to accommodate sudden hot machine shutdowns. Water cools the bearings during this event, preventing bearing seizure. The C15 engine also includes a new turbine housing and an additional spacer bearing. The addition of a spacer bearing eliminates snap rings and, therefore, reduces complexity and improves shaft motion. The turbocharger uses an aluminum compression wheel. Changes enable the C15 to deliver longer life and lower maintenance costs and contribute to good fuel economy. The design also provides high horsepower with improved response time while keeping exhaust temperatures low for long hours of continuous operation. The waste-gate turbocharger design improves engine response and peak torque, while providing higher boost over a wider range.

The Cat MEUI fuel system combines the technical advancement of electronic control with the simplicity of direct mechanically controlled unit fuel injection. This system electronically controls injection pressure by sensing the engine speed and load conditions over the entire engine operating speed range. A low-pressure fuel transfer pump provides fuel to the injectors, which then increases the pressure to deliver very fine, atomized fuel particles into the combustion chamber with precise timing and duration. The result is a more complete fuel burn with lower emissions and better engine response.

The 770 is equipped with three oil coolers: an engine-mounted engine oil cooler, an engine-mounted transmission/torque converter oil cooler, and a remote-mounted, brake, hoist and hydraulic fan oil cooler. These coolers allow major components to expel heat, maintaining optimal operating temperatures.

The C15 engine is equipped with two fuel filters. The primary filter is machine-mounted and features oil/water separation and an electric priming pump. The electric pump provides easier priming and better contamination control than a manual unit. The secondary fuel filter is also machine mounted, and has a switch that monitors pressure changes and provides pressure drop warnings to the operator.

The ADEM A4 electronic control module provides flexible fuel mapping, allowing the engine to respond quickly to varying application needs.

The new modular cooling system with a single-pass flow core design uses brazed construction for stronger joints, better leak prevention and higher heat transfer. The simpler design of the single-pass system, which replaces the two-pass flow folded core system enables coolant to enter one end of the core and flow out the opposite end for more efficient ambient cooling capability and greater durability.

The 770 includes a standard, variable-speed, on-demand fan. This fan provides cooling airflow only when necessary, resulting in reduced parasitic losses, a reduction of fuel consumption and fan-generated noise. The C15 engine includes a Poly-V accessory drive belt with an auto-tensioner, which is self adjusting.

The Cat mechanical drive power train and power shift transmission provides unmatched operating efficiency and control on steep grades, in poor underfoot conditions, and on haul roads with high rolling resistance.

Pairing the Caterpillar seven-speed planetary power shift transmission with the C15 diesel engine with ACERT Technology delivers constant power over a wide range of operating speeds.

Transmission shifting is based on Transmission Output Speed for optimum performance efficiency and clutch life. The TCC provides integrated functionality to controlled throttle shifting, directional shift management, neutral coast inhibitor, body-up shift limiter and body-up reverse neutralizer.

The operator can now electronically lock the throttle pedal at full throttle, to reduce fatigue on long uphill hauls. The throttle can be locked on by momentarily depressing the throttle lock switch located on the operator console, while depressing the pedal fully. The throttle is released whenever braking is applied or the throttle is again depressed.

Combines maximum rimpull and cushioned shifting of torque converter drive with the efficiency and performance of direct drive. The torque converter includes: an additional clutch plate to maintain power train capability for higher horsepower and top speed, a new torque converter adapter that provides extra length to house the additional clutch plate and enables the converter components to be changed without having to change the housing, and a new sump oil level switch that serves as an emergency warning if oil is lost. The lock-up torque converter engages at approximately 8 km/h (5 mph), delivering more power to the wheels.

Quickly releases and re-engages to reduce power train torque loads for smoother shifting, long life and a more comfortable ride.

The new Cat differential works with the proven final drives as a system to deliver maximum power to the ground. For improved serviceability, the pinion gear is cantilever mounted, which allows inspection of the differential without pulling the rear-end. Visual inspection of the pinion gear and bearings can be performed in 1-2 hours versus 8 hours on the previous models. In addition, the differential bevel pinion gear set is designed for improved adjustability, which results in improved contact patterns and life. The differential gear set also provides enhanced bending life for steeper grade applications.

A new, ductile iron center housing improves quality and reliability. The improved stiffness allows for better main support bearing life. The new housing also uses bolts, reducing maintenance time. This change also improves wheel station bolted-joint life.

The new A-frame mounts directly to the spindles. The new A-frame eliminates the “king” bolt and includes a pin and bushing style mounting, consistent with the 777 and 793. This new design is simpler to maintain and service.

A stress-optimized, ductile iron spindle is splined to the rear brakes, reducing brake pack rebuild time by up to two hours. In addition, the spindles are longer and wider with fewer seals for increased strength and durability.

A single-piece brake anchor eliminates more than 200 fasteners and a row of bolted joints. Rebuild time is reduced by up to two hours. In addition, the brake pack is removable without taking the spindle off the truck. The 770 features 24 brake discs. The brake discs have increased in diameter from 19 to 21 in (482.6 to 533.4 mm). By increasing the diameter, Caterpillar has improved the overall reliability and durability of the brake packs and has also designed the brake packs to improve the OD/ID ratio. The new 770 brake pack design, moves the braking forces to the outer edge of the disc, thereby using greater surface area for improved braking forces and longer life, improving reliability and lowering maintenance cost.

The wheel stations now integrate both the wheel and the hub. The single-piece design reduces removal and installation time, and the risk of brake cooling oil leakage. The inner Duo-cone™ seal has been changed from a formed type to a cast design. Brake cooling flow and the Duo-cone seal has also been reversed for better sealing performance and improved seal life. Wheel stations are now interchangeable, reducing the number of replacement parts: left and right wheel stations are symmetric and can be interchanged. In addition, the new design eliminates one o-ring seal, which improves reliability and simplifies the system and the wheel bearings have been enhanced for longer bearing life.

The 770 uses 18.00R33 tires as the standard tire configuration.

Hydraulic steering control system is designed for exceptional smoothness and precise control. A separate circuit prevents cross contamination for long life.

A battery powered supplemental steering system uses pressure accumulators and allows up to three 90 degree turns in case of engine failure.

Cast rear wheels and Cat center-mount rims are mounted using studs and nuts to minimize maintenance and maximize durability.

The 770 frame uses a box-section design, incorporating two forgings and 13 castings in high-stress areas with deep penetrating and continuous wrap-around welds to resist damage from twisting loads without adding extra weight.

Mild steel used throughout the frame provides flexibility, durability and resistance to impact loads, even in cold climates and allows for easy field repairs.

Castings have large radii with internal reinforcing ribs to dissipate stress in areas of high stress concentration. Castings move welds to lower stress areas for greater frame life.

Resiliently mounted to the main frame with all-new cab mounts that reduce vibration and sound, the integral ROPS is designed as an extension of the truck frame. The ROPS/FOPS structure provides “five-sided protection” for the operator.

Structural frame welds are J-groove type, ensuring full weld penetration for strength and longevity. During fabrication, weld integrity is further enhanced by rotating the frames 360 degrees to provide optimal, flat welding surfaces.

Caterpillar structures are tested using System Structural Analysis (SSA) to dynamically simulate operations in field environments and identify potential structural improvements in high stress areas. With analysis of machine structures and variables, such as haul road and payload, structural improvements were made to the frame to accommodate the new cab, platform, engine and radiator.

A Coordinate Measuring Machine (CMM) is used to inspect truck frames for consistency in the manufacturing process. In addition, all critical welds receive testing to verify weld penetration, which results in frame durability.

Electronically integrates machine computer systems to optimize overall power train performance, increase reliability and component life, and reduce operating costs. All the information from these controls can be accessed through a laptop computer with Cat ET.

TCC uses electronically transferred engine rpm data to execute shifts at preset points for optimum performance, efficiency and clutch life.

Cat ET service tool provides service technicians with easy access to stored diagnostic data through the Cat Data Link to simplify problem diagnosis and increase machine availability. Cat ET is beneficial because of how it displays the status of all engine parameters, including throttle position, timing and fuel flow. Critical data from the electronic engine and transmission controls, including transmission shifting, engine speed and fuel consumption, provides service technicians with enhanced diagnostic capability to reduce downtime and operating costs.

Regulates engine rpm during shifting to reduce power train stress and clutch wear by controlling engine speed, torque converter lock-up and transmission clutch engagement for smoother shifts and longer component life.

Regulates engine speed during directional shifts to prevent damage caused by high-speed directional changes.

Prevents the transmission from shifting to neutral at speeds above 6.5 km/h (4 mph), protecting the transmission from operating with insufficient lubrication.

Prevents the transmission from shifting above a pre-programmed gear without the body being fully lowered. This function is programmable via Cat Electronic Technician (Cat ET) and Messenger.

Automatically shifts the transmission to neutral if the hoist lever is activated while the transmission is shifted in reverse.

The transmission control electronically senses engine conditions and automatically up-shifts one gear to prevent overspeeding. If overspeeding occurs in the top gear, the lock-up clutch is disengaged, and the brakes are applied.

Transmission top gear maximum can be set using Cat Messenger or the Cat ET service tool to help the operator maintain speed limits.

This function minimizes shifting by not allowing the transmission to up or down shift immediately after a shift has occurred. This prevents gear hunting when operating near a shift point and minimizes transmission shifting for increased component life.

Prevents engine overspeeding by keeping the transmission from downshifting until engine speed reaches the downshift point.

Modifies engine maps for better fuel economy.

Air conditioning

Cat C15 Engine with ACERT® Technology

Extended Life Coolant to -35°C (-30°F)

Alarm, backup

Product Link Ready

Engine crankcase

Suspension, front/rear (European Union compliant)

Body mounting group (flat floor or dual slope body)