You'll burn less fuel and get more power because of Caterpillar's advances in engine technology and machine design. This includes an on-demand cooling fan that only spins when needed and, therefore, draws less engine power.

Serviceability has been reinvented with the C Series - the first and only wheel feller buncher that can be serviced standing on˛the ground. This includes fueling. Many other features contribute to the ease and safety of servicing the C Series machines: hinged access panels, tilting cab, and three-sided access to the engine and hydraulic pumps, to name a few.

Power, stability, agility and superior multi-functioning capability work together to give you the performance you need to maximize productivity. The engines deliver power where and when it is needed as a result of PowerDirect Plus, a new system that optimizes machine efficiency, performance and productivity. You'll see better performance in all applications on both steep and flat ground. Simultaneous lift-tilt and lift-steer functions and saw recovery are significantly faster than major competitive machines.

Place trees where you want with the unmatched cut and carry capability of the C Series. The engine was placed at the back of the machine providing better weight distribution and balance. The center hitch is positioned between the front and rear axles to facilitate tire tracking. Combined with the improved weight distribution and balance that results from the rear engine position, the agility of the C Series is a distinct advantage.

Robust box section frames and a field-proven center hitch design provide a solid foundation for a machine designed to keep you in the woods. New components - like the control valve, pumps and cylinder seals - were “torture” tested to ensure reliability. Steering cylinder mounts and chrome plated lift arm and tilt link pins are two more examples of structural changes built into the C Series to increase uptime and machine life.

The cab is centered between the axles for a smooth ride. The standard air suspension seat with neck and back support and new high capacity HVAC system adds to your comfort. A clean three-piece front windshield, large rear windows and skylight give you a 360º view, including the rear tires. The C Series features additional functions including Control Adjustability, Terrain Selection Mode, Creep Mode, and Road Steer Mode.

The Cat C6.6 ACERT engine performs at U.S. Tier 3 and EU Stage IIIA emission levels and provides clean, quiet operation while delivering superior performance and durability. The engine features a flat power curve for outstanding response in the working RPM range, noise reduction technologies, and patented ACERT Technology combined with common rail fuel system, smart waste gate turbocharger and crossflow head design for reduced emissions.

Both engines allow the use of biodiesel (meeting ASTM 6751 or EN 14214) up to B20 (biodiesel 20 percent mixture).

The high capacity cooling system and on-demand reversing fan keep the machine running at the proper operating temperature, optimizing performance, durability and fuel efficiency.

The cooling system is arranged in two panel sections for easy access to all components. The air conditioning condenser is in a hinged panel that tilts out for easy cleaning and access to the primary section with the side-by-side mounted hydraulic oil cooler, engine radiator and air to air after cooler (ATAAC).

The oversized, hydraulically driven fan spins at a slower speed overall and only turns as fast as needed to maintain proper hydraulic and engine temperatures. In colder weather or when the machine is first started, for example, the fan spins more slowly to conserve power and fuel and reduce noise. Air is pulled in from the side - not from the engine or from under the hood - preventing debris build-up around the engine. It automatically reverses every five minutes of run time to keep the cooling system free of debris. A manual override allows the operator to activate reversal between scheduled cycles. A heavy-duty fan shroud provides protection when servicing.

Cat engines, field-proven hydrostatic drive and Cat axles make a solid, responsive power train. A new design to keep the pump drive and gearbox well lubricated provides even more durability.

Caterpillar's C Series design features a dual pad pump drive. One drive runs the attachment and main pumps; the other runs the hydrostat and fan pumps. The improved dual pad pump drive is more durable because it is not dependent on splash lubrication.

Similar to the pump drive, the two-speed gearbox is now mounted horizontally instead of vertically, eliminating the need for splash lubrication and improving durability.

Axles feature a full-length oil sump for excellent heat rejection and long component life when using single tires (up to 30.5 × 32 with chains), odd size dual tires (up to 30.5 × 32 with 24.5 × 32), or wide flotation tires (up to 73 × 44). An oscillating rear axle absorbs shock loads caused by stumps and holes and helps isolate the cab from axle movement for a smooth, comfortable ride, while maximizing fore-aft stability.

The inline parking brake is spring applied and hydraulically released. Inboard service brakes provide excellent performance and are protected from water, dust and oil.

During normal operation all four wheels move independently to maximize agility. In extreme conditions like slippery or steep terrain, pressing and holding a trigger button on the joystick will engage the front differential lock to make the front tires turn in sync. The rear differential lock is easily engaged and disengaged by an on/off button on the right hand console.

Robust box section frames provide a solid foundation for a machine designed to keep you in the woods. Every structure was engineered for durability and verified through lab and field tests.

The field-proven center hitch design features large dual tapered roller bearings and 76.2 mm (3 in) diameter pins providing maximum durability. With up to 90º articulation, maneuverability in tight thinning stands is an advantage of the Cat wheel feller bunchers.

The precision manufactured lift arms are rugged and designed to support severe loading from the attachment.

Lift arm and tilt link pins are 63.5 mm (2.5 in) diameter and chrome-plated to prevent corrosion. Micro‑cracks in the chrome plating help retain grease on the pin surface to increase durability.

The steering cylinders are mounted to large, thick plates that are integrated into the frame and extend from the steering cylinders in the center hitch to the axle housings in the front and rear of the machine. These plates carry the steering cylinder force straight to the axles, rather than sending the load through the machine's frame, increasing structural life.

The heart of the C Series hydraulic system is the new PowerDirect Plus system, which goes beyond load sensing to efficiently distribute power to increase the capability of each system and maximize productivity.

The new C Series features an electrohydraulic control system. The pedals and joysticks communicate through the machine controller to the pumps and motors using electrical signals, rather than hydraulic, to produce more precise and smoother control.

PowerDirect Plus is a new system that optimizes the machine's performance by monitoring operator and attachment demand and delivering power where and when it is needed. PowerDirect Plus does not require the operator to reduce demand or do anything differently - just focus on the work and push the machine. Critical machine systems in the C Series are oversized, which increases overall machine capacity. This gives each machine system - hydrostat, main, attachment and fan - more capability than ever before. PowerDirect Plus provides better performance in all applications on both steep and flat ground. If you're carrying a tree in the head and backing up a hill, the system will focus full power to the drivetrain. On flat ground where drivetrain demand is lower, more power is available to the attachment and the oversized attachment pump pushes more flow to the saw. Saw recovery time is significantly faster compared to previous wheel feller bunchers.

Multi-functioning, always an advantage for Cat wheel feller bunchers, is the result of a high performance control valve. In addition to field-testing, we put the control valve and hydraulic pumps through extensive lab “torture” tests that simulated the most brutal logging conditions and environment. The tests verified a significant increase in the service life of the control valve and pumps.

Rigorous testing similar to the control valve and pumps and side-by-side testing against competitive cylinders was conducted on the new cylinder seal packages to ensure durability.

Dual spin-on hydraulic oil filters keep hydraulic oil clean, which is critical for machine health. The electric fill pump uses a quick coupler hose stored on the machine to pump oil through the filtration system before it enters the tank, safeguarding the hydraulic system.

Cat ToughGuard™ hoses and O-ring face seals throughout the machine improve machine life and reliability, particularly along the lift arms and through the center hitch due to the increased strength and flexibility. The ToughGuard cover consists of a layer of UHMW polyethylene bonded to the rubber cover, providing exceptional abrasion resistance. Extreme-duty rubber tube covers provide additional protection to the lift arm hoses. The covers reduce downtime by deflecting impact to the hoses from debris.

Comfort and visibility, of course, but you'll find cab features that go beyond the basics to give you control options that can be customized and new operating functions, including special modes for thinning, road travel and terrain settings.

Sit on either end of a teeter-totter and feel every bump; sit in the center and get a level, smooth ride. This principle applies to the new C Series. The cab is centered between the axles for the most comfortable ride possible. No bucking. The standard air suspension seat with neck and back support adds to a smooth ride, keeping the operator comfortable and focused.

The durable, high capacity HVAC (heating, ventilation, and air conditioning) system provides dependable cooling or heating no matter how hot or cold it gets. Vents in front and on both sides can be directed toward the operator or the windows. This also contributes to increased operator productivity and can help reduce mental and physical fatigue at the end of the day.

A clean three-piece front windshield, large rear window and skylight give the operator a 360° view, including the rear tires. The operator can see the work zone easily without having to strain or move the machine around all day. With a clear view to the treetops, picking out the bad or stunted trees in thinning jobs is faster.

The display allows the operator to continuously monitor the machine's systems. Early indications give the operator the opportunity to react before potential problems become actual problems. A clean and clear monitor provides detailed machine data to maximize machine uptime and productivity. Finding information is intuitive:

• The home screen displays the condition of primary systems, such as fuel level, engine and hydraulic temperatures, and engine and saw rpms. Press the corresponding button along the bottom of the screen to get more detail on any item. As an example, under the hydraulic system selection, the two-speed gearbox oil level indicator is displayed.
• If an engine or hydraulic problem occurs, the monitor will display an easy-to-understand text explanation, along with any applicable fault codes.
• If a machine condition requires immediate action, a warning buzzer will sound to draw the operator's attention to the monitor. The operator must acknowledge the warning to turn off the alarm. Depending on how serious the warning, the alarm will continue to sound until the condition is remedied.
• Everything the system does is recorded in the system log, a useful feature for monitoring machine health and operator activity.

All key operator functions - steering, lift and tilt - are fully adjustable through the machine monitor. Overall speed and response to operator input can be adjusted, maximizing operator comfort and performance. The gathering arm and bunching finger controls also are easily reversed, if the operator is used to that configuration.

New electrohydraulic joysticks mold to the operator's hands for all day comfort and increased functionality. Converting to electrohydraulic control also means the hydraulic pilot lines running to the joysticks could be removed, eliminating a potential source of heat in the cab.

The button pad on the right hand console features on/off buttons clearly labeled with large icons for many features, including the parking brake, hydraulic arming and reversing fan.

Unique operating modes, combined with complete electrohydraulic controls, provide the operator with a smoother machine with increased productivity. These modes include Terrain Selection Mode to optimize performance on hills or flat ground, Creep Mode to improve machine functionality, particularly in first thinnings, and Road Steer Mode for high-speed transport of the machine.

• Terrain Selection Mode: Quickly and easily optimize machine performance based on application requirements. Select Hill Mode to boost drivetrain power for working in rough conditions like hills, wet ground or bedded plantations. Select Flat Mode to maximize speed and optimize fuel efficiency when ground conditions are good.
• Creep Mode: A great feature for first thinning applications, Creep Mode gives the operator the ability to dial down the speed of the machine when a propel pedal is depressed completely. This allows the operator to keep the pedal depressed - rather than continually having to start and stop - while working down a row of trees. No need for feathering to find that sweet spot - just relax and push the pedal completely down. The Creep Mode makes it easy to get into a steady rhythm of cutting, gathering and dumping. Productivity is increased and operator fatigue reduced. Here's how it works: On the monitor set the Creep Mode speed to the percent of maximum machine speed desired. Hit the creep button on the joystick and fully depress the forward pedal to move forward at the set speed. Cut the first tree, cycle the arms; cut the second tree, cycle the arms, etc. When the head is full, hit the Creep Mode button again to regain full speed while backing up, dumping and driving back to the trees. Hit the Creep Mode button and depress the forward pedal to go back into Creep Mode and begin cutting again.
• Road Steer Mode: Fast steering is required when working in the woods, but slower steering is preferable when driving down a road to a new job site. Road Steer Mode slows the joystick's response so the operator can steer the machine safely to the next site.

Cat C6.6 Engine with ACERT™ Technology

OPS/FOPS/ROPS Certified Cab

Cross-Flow Cooling System

Cat Axles

HD Front and Rear Frames

PowerDirect Plus System

24-Volt Electrical System

Reverse Slope 3-piece Windshield

Operator Control Adjustability

Pressurized Engine/Hydraulic and Cat CEM Compartments