320D FM Forest Machine

320D FM Forest Machine

The D-Series Forest Machines are powered with ACERT® Technology and Caterpillar quality from undercarriage to grapple. These rugged, state-of-the-art forest machines provide both reliability and durability for the most demanding logging environments.

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Power Train

The Cat® C6.4 has exceptional power and fuel efficiency unmatched in the industry for consistently high performance in both forestry and millyard applications.

Cat C6.4 ACERT™

The Cat® C6.4 with ACERT™ Technology gives the 320D FM exceptional power and fuel efficiency unmatched in the industry. The C6.4 meets U.S. EPA Tier 3 emissions requirements. The forestry designed hydraulics give the 320D FM exceptional power, efficiency and controllability unequaled in the industry for consistently high performance in all forestry applications.


The 320D FM is equipped with the C6.4 ACERT engine, which provides 7% more horsepower as compared to the Cat 3066 T engine.

Automatic Engine Speed Control

The two-stage, one-touch control maximizes fuel efficiency and reduces sound levels.

ADEM™ A4 Engine Controller

The ADEM A4 electronic control module manages fuel delivery to get the best performance per liter of fuel used. The engine management system provides flexible fuel mapping, allowing the engine to respond quickly to varying application needs. It tracks engine and machine conditions while keeping the engine operating at peak efficiency.

Electronic Control Module

The Electronic Control Module (ECM) works as the “brain” of the engine’s control system, responding quickly to operating variables to maximize engine efficiency. Fully integrated with sensors in the engine’s fuel, air, coolant, and exhaust systems, the ECM stores and relays information on conditions such as RPM, fuel consumption, and diagnostic information.

Fuel Delivery

The Cat C6.4 ACERT™ features electronic controls that govern the fuel injection system. Multiple injection fuel delivery involves a high degree of precision. Precisely shaping the combustion cycle lowers combustion chamber temperatures, generating fewer emissions and optimizing fuel combustion. This translates into more work output for your fuel cost.

Cooling System

The cooling fan is directly driven from the engine. An optional programmable reversible fan allows for radiator blowout, to increase service intervals and to maintain engine operational temperatures. The optimum fan speed is calculated based on the target engine speed, coolant temperature, hydraulic oil temperature and actual fan speed. The Cat C6.4 ACERT delivered a completely new layout that separates the cooling system from the engine compartment.

Air Cleaner

The radial seal air filter features a double-layered filter core for more efficient filtration and is located in a compartment behind the cab. A warning is displayed on the monitor when dust accumulates above a preset level.

Noise Reduction Technologies

The engine mounts are rubber-isolating mounts matched with the engine package. Further noise reduction has been achieved through design changes to the isolated top cover, oil pan, multiple injection strategy, insulated timing cover, sculpted crankcase and gear train refinements.


Cat® hydraulics provide the power and control needed for a variety of applications.

Component Layout

The 320D FM hydraulic system and component locations have been designed to provide a high level of system efficiency. The main pumps, control valves and hydraulic tank are located close together to allow for shorter tubes and lines between components that reduce friction loss and pressure drops in the lines. The layout further provides greater operator comfort by placing the radiator on the cab side of the upper structure. This allows incoming air to enter the engine compartment from the operator side and hot air and corresponding engine sound to exit on the opposite side away from the operator. This reduces engine compartment heat and sound being transmitted to the operator.

Pilot System

The pilot pump is independent from the main pumps and controls the front linkage, swing and travel operations.

Hydraulic Cross Sensing System

The hydraulic cross sensing system improves productivity with faster implement speeds and quicker, stronger pivot turns.

Boom and Stick Regeneration Circuit

Boom and stick regeneration circuit saves energy during boom-down and stick-in operation which increases efficiency, reduces cycle times and pressure loss for higher productivity, lower operating costs and increased fuel efficiency.

Fine Swing Control

Standard fine swing control cushions start and stop for better implement control.


The hydraulic system offers precise control to the 320D FM reducing operator fatigue, improving operator effectiveness and efficiency, which ultimately translates into enhanced performance.

Auxiliary hydraulic Valve

The auxiliary valve is standard on the 320D FM. Control Circuits are available as attachments, allowing for operation of high and medium pressure tools such as grapples.

Hydraulic Cylinder Snubbers

Snubbers are located at the rod-end of the boom cylinders and both ends of the stick cylinders to cushion shocks, reduce sound and increase cylinder life, increasing uptime and productivity.

Operator Comfort

The purpose built forestry cab interior layout maximizes operator space, provides exceptional comfort, provides excellent sightlines and reduces operator fatigue.

Operator Station

The workstation is spacious, quiet and comfortable, assuring high productivity during a long work day. Controls, joysticks and an ergonomically designed seat reduces operator fatigue.


The monitor is a full color 400 X 234 pixels Liquid Crystal Display (LCD) graphic display. The monitor angle can be adjusted to minimize sun glare and has the capability of displaying information 27 different languages.

Pre-Start Check

Prior to starting the machine, the system will check for low fluid levels for the engine oil, hydraulic oil and engine coolant and warn the operator through the monitor in the event display area.

Gage Display

Three analog gauges, fuel level, hydraulic oil temperature and coolant temperature, are displayed in this area.

Event Display

Machine information is displayed in this area with the icon and language.

Multi-Information Display

This area is reserved for displaying various information which is convenient for the operator. The “Cat” logo is displayed when no information is available to be displayed.


Seat provides a variety of adjustments to suit the operator’s size and weight including fore/aft, height and weight. Wide adjustable armrests and a retractable seat belt are also included.

Joystick Control

Joystick controls have low lever effort and are designed to match the operator’s natural wrist and arm position. The operator can operate joystick controls with an arm on the armrest and the horizontal and vertical strokes have been designed to reduce operator fatigue. Exclusive proportional control and push buttons are programmable to operator personal preferences, allowing maximum productivity.

Hydraulic Activation Control Lever

For added safety, this lever must be in the operate position to activate the machine control functions.


Redesigned consoles feature a simple, functional design to reduce operator fatigue, ease of switch operation and excellent visibility.


An enlarged skylight with sunshade provides excellent upwards visibility.


Cab design optimizes post structures, and scratch-resistant polycarbonate window placement to provide excellent operator visibility to front, sides and rear. Forestry cab is designed with heavy-duty guarding, meeting FOPS/OPS/FOGS/TOPS and CB requirements.


Purpose-built forest applications with reinforced carbody, rugged swing bearing, heavy doors and extra guarding.

Rugged main frame design maximises durability

  • Outer frame utilizes curved side rails, which are di-formed for excellent uniformity and strength.
  • Box-section channels improve upper frame rigidity under the cab.
  • Inverted U-channels span the width of the main frame and are formed,rather than fabricated, for superior strength and reduced weight.
  • Boom tower and main rails are constructed of solid, high-tensile strength, steel plates.
  • Boom foot and engine mount areas are reinforced for additional strength.
  • Sheet metal supporting structure is improved by integrating the mounting into the upper frame structure.

Carbody Design

Advanced, reinforced, purpose-built carbody design stands up in the toughest forest applications.

Carbody Structure

Wide, tall, and thick carbody structure provides operating stability and durability while improving operation’s effectiveness.

  • Upper structure weight and stresses are distributed evenly across the full length of the track roller frame.
  • Smooth transitions and long welds help reduce stresses at the carbodyto-roller frame junctions for excellent durability.
  • Robot welding helps ensure consistent, high-quality welds throughout the manufacturing process.


Caterpillar guarding protects your forestry machine investment.

Shoe Support Guards

Standard fulllength track shoe support guards help protect rollers and provide increased rigidity to track links in rough underfoot conditions.

Factory Forestry Cab

Caterpillar factory forestry designed and built FOPS cab has options for windshield guard and window guards to meet local guarding requirements. The right side and rear windows are made from impactresistant polycarbonate.

Heavy-Duty Access Doors

Heavy-duty access doors are standard on the 320D FM and are made from 6 mm (0.24 in), high-strength, low alloy steel. Positive locking latch stays closed in forestry applications. Hinges have larger diameter pins over standard doors. The smooth door profile enhances machine appearance.


Durable undercarriage absorbs stresses and provides excellent stability.

Heavy-Duty Top Rollers

Track rollers with dual supports replace carrier rollers to assure superior endurance.

Heavy-Duty Track Rollers

Heavy-duty track rollers stand up to the toughest forest applications. Features include greater sealability, higher resistance to deformation and greater load carrying capacity.

Heavy-Duty Grease Lubricated Track

The 325 HD Track Link with 8 inch pitch and 8 bottom rollers is standard on the 320D FM.

1) Grease Lubricated Track

  • Extends internal bushing wear life
  • Reduces noise
  • Provides more usable horsepower because of decreased internal friction
  • Reduces chance for frozen track


2) 10% Larger Bushing Diameter

• Extends external bushing wear life

3) Greased Pin and Larger Bushing Combined

  • Extends system life
  • Reduces sprocket wear because the system stays matched longer
  • Improves balance in component

wear life

4) 15% Increase in Link Height

• Increases link wear life

5) 36% Wider Bushing Strap

• Improves bushing-to-link retention

6) Unique Pin Retention System

• Locks the pin to the link


A wide selection of Forest Machine configurations meet diverse forestry applications and improve your productivity.

The Caterpillar Log Loader is Purpose

The Caterpillar log loader is purpose built for forest applications. Completely assembled, heel-type log loaders (including grapple) are available from the factory.

The Caterpillar Heel-Type Loader Arrangements

The Caterpillar heeltype loader arrangements fit a wide variety of log handling and loading applications in the woods and millyards. Heel booms are especially well-suited for use with large diameter sawlogs and tree length loads.

Caterpillar Roadbuilders

Caterpillar Roadbuilders can be equipped with buckets, thumbs, clamshells and clearing grapples to fit a wide range of forest road jobs.

Applications Include

Moving right-of-way logs, stumping, pioneering, stripping organic material, excavating shot rock, truck loading, back sloping, ditching, finish grading and slash piling.

The Caterpillar 320D FM Delimber Carrier

The Caterpillar delimber carrier can be fit with a variety of AEM delimbers.

Caterpillar Grapples

Caterpillar Forest Machines combined with Cat Log Loading Grapples mean optimal performance, reliability and on-the-job productivity.

Cat 360 Degree Continuous Rotating Log Loader Grapples

Cat 360 Degree Continuous Rotating Log Loading Grapples for Forestry Machines are high capacity tools, built for endurance in high-volume logging applications. GLL grapple legs are made of high-strength alloy steel with unique leg profiles for maximum performance in picking/sorting, bunching/loading or shoveling applications. Large bunches of stems or single large logs are easily handled by the wide grapple opening (60"/1524 mm), while interlocking legs close down to 5"/127 mm for picking and sorting. Cat grapples have bolt-on access panels allowing for easy serviceability and are backed by the world-class Caterpillar Dealer Network.

360-Degree Continous Rotation

High torque hydraulic motor positions the grapple precisely for rapid sorting and loading.

Hydraulic Cylinders

Heavy-duty wall construction delivers durability and maximum closing power move the maximum amount of wood per pass.


Built with high-strength alloy steel for maximum durability. Optimized profile performs equally well whether sorting, bunching or shoveling.


Induction-hardened alloy pins float, decreasing wear.


Bolt-on access panels protect the grapples internal components, while providing easy access. Long service intervals and infield servicing result in more uptime and lower operating costs.

Owning and Operating Costs

Caterpillar Forest Machines provide the best value for your forestry and millyard applications.

ACERT™ Technology Fuel Economy

Based on Caterpillar testing, the fuel economy of Cat engines with ACERT technology is 3 to 5 percent better than current competing technologies. This fuel economy is directly related to the complete combustion of fuel due to the integration between the electronic control that monitors conditions, the air management system that controls air volume and the fuel injection system that delivers just the right amount of fuel as needed.

Radiator Compartment

The radial air filter has a double layered filter core for more efficient filtration and is located in a compartment behind the cab. Easy access doors allows for easy, faster cleanout minimizing down time. Heavy-duty screen filters assembled on the door keep debris away from the radiator compartment, extending service intervals.


Simplified service and maintenance features save you time and money.

Ground Level Service

The design and layout of the 320D FM was made with the service technician in mind. Many service locations are easily accessible at ground level allowing critical maintenance to get done quickly and efficiently.

Air Filter Compartment

The air filter features a double-element construction for superior cleaning efficiency. When the air cleaner plugs, a warning is displayed on the monitor screen inside the cab. Pump Compartment. A service door on the right side of the upper structure allows ground-level access to the pump and pilot filter.

Radiator Compartment

The left rear service door allows easy access to the engine radiator, oil cooler and air-to airaftercooler. A reserve tank and drain cock are attached to the radiator for simplified maintenance.

Grease Lubricated Track

Grease lubricated seals protect the track link and deliver long track pin and bushing inner wear life.

Capsule Filter

The hydraulic return filter, a capsule filter, is situated outside the hydraulic tank. This filter prevents contaminants from entering the system when hydraulic oil is changed and keeps the operation clean.

Fan Guard

Engine radiator fan is completely enclosed by fine wire mesh, reducing the risk of an accident.

Anti-Skid Plate

Anti-skid plate covers top of storage box and upper structure to prevent slipping during maintenance.

Diagnostics and Montoring

The 320D FM is equipped with S•O•SSM sampling ports and hydraulic test ports for the hydraulic system, engine oil, and for coolant. A test connection for the Cat Electronic Technician (Cat ET) service tool is located in the cab.

Extended Service Interval

320D FM service and maintenance intervals have been extended to reduce machine service time and increase machine availability.

Customer Focus

Caterpillar dealer services help you operate longer with lower costs.

Product Support

You will find nearly all parts at our dealer parts counter. Cat dealers utilize a worldwide computer network to find in-stock parts to minimize machine down time. Save money with remanufactured components.

Machine Selection

Make detailed comparisons of the machines you are considering before you buy. What are the job requirements, machine attachments and operating hours? What production is needed? Your Cat dealer can provide recommendations.

Customer Support Agreements

Cat dealers offer a variety of product support agreements, and work with customers to develop a plan the best meets specific needs. These plans can cover the entire machine, including attachments, to help protect the customer’s investment.


Improving operating techniques can boost your profits. Your Cat dealer has videotapes, literature and other ideas to help you increase productivity, and Caterpillar offers certified operator training classes to help maximize the return on your investment.

Maintenance Services

Repair option programs guarantee the cost of repairs up front. Diagnostic programs such as Scheduled Oil Sampling, Coolant Sampling and Technical Analysis help you avoid unscheduled repairs. Replacement. Repair, rebuild, or replace? Your Cat dealer can help you evaluate the cost involved so you can make the right choice.


Engine Model
Cat® C6.4 ACERT™
Net Flywheel Power
ISO 9249
EEC 80/1269


General Forestry (HW)
General Forestry (HD/LC)
Log Loader (U/U)

Swing Mechanism

Swing Torque - General Forestry
45611.0lb ft
Swing Speed - General Forestry

Service Refill Capacities

Fuel Tank
Fuel Tank - Optional Auxiliary Right Front
Maximum Fuel with all Optional Tanks
Cooling System
Engine Oil
Swing Drive
Final Drive (each) - (HW)
Final Drive (each) - (HD/LC)
Hydraulic System (including tank)
Hydraulic Tank


SAE J1026 APR90
SAE J1356 FEB88 ISO 10262/SAE J1084/ISO 8084/OR-OSHA 437-007-0775/WCB G602, G603, G604, G608

Hydraulic System

Main Implement System - Maximum Flow (2x)
Maximum Pressure - Implements
Max. pressure - Travel
Max. pressure - Swing
Pilot System - Maximum Flow
Pilot System - Maximum Pressure
Boom Cylinder - Bore
Boom Cylinder - Stroke
Stick Cylinder - Bore
Stick Cylinder - Stroke

Excavator Linkage

Boom Cylinder - Bore
Boom Cylinder - Stroke
Stick Cylinder - Bore
Stick Cylinder - Stroke
B1 Family Bucket Cylinder - Bore
B1 Family Bucket Cylinder - Stroke

Log Loader Linkage

Boom Cylinder - Bore
Boom Cylinder - Stroke
Stick Cylinder - Bore
Stick Cylinder - Stroke
Under/Under Heel Cylinder - Bore
Under/Under Heel Cylinder - Stroke


Maximum Travel Speed (HD/LC)
Maximum Drawbar Pull (HD/LC)
Maximum Travel Speed (HW)
Maximum Drawbar Pull (HW)

Standard Equipment

  • Electrical
    • 80 Ampere alternator
    • 4 Front working lights, cab top mounted
    • 2 Front working lights, riser mounted
    • 1 Left side working light, cab mounted
    • 1 Rear working light, cab mounted
    • Horn
  • Operator Environment
    • Purpose built forestry cab with 8 lights and all scratch resistant polycarbonate windows
    • Seat, four-way adjustable suspension seat with adjustable armrest, retractable seatbelt, headrest and lumbar support
    • Integrated seat, console and joystick type controls
    • Language display monitor with gauges
    • Warning information Filter/fluid change information working hour information machine condition error code and tool mode setting information start up level check for hydraulic oil, engine oil and engine coolant
    • Full time clock on monitor (2 weeks)
    • Seat mounted joystick with extra functions for grapple
    • Fixed polycarbonate skylight with retractable sun shade
    • Interior lighting
    • Lower and upper windshield wipers and washer
    • Positive filtered ventilation, pressurized cab with bi-level air conditioner, heater and defroster with manual control
    • Forced air fan
    • 2 post mounted fresh air vents
    • Behind seat storage tray with tie down points
    • 2 CB radio mounts
    • 1 Fire extinguisher mount
    • 1 Attachment computer control mount
    • Secondary roof exit openable from inside and outside
    • 2 Coat hooks
    • Ashtray with lighter
    • Literature holder
    • Cup holder
    • Neutral lever for all controls
    • Travel control pedals with removable hand levers
    • Washable floor mat
    • Radio/CD player (12V)
    • 1 Converter/2 sockets - 12V-10A power supply
  • Power Train
    • CAT C6.4 with ACERT Technology U.S. EPA Tier 3 emissions compliant with 24-volt electric starting and air intake heater
    • Automatic engine speed control with one touch low idle
    • Easy clean swing-out condenser
    • Easy clean swing out radiator
    • Muffler
    • Two speed auto-shift travel
    • Water separator in fuel line
  • Undercarriage
    • Hydraulic track adjusters
    • Track type undercarriage with grease lubricated seals
    • Idler and full-length track shoe support
  • Other Standard Equipment
    • Heavy-duty upper frame with catwalks, bottom guards, heavy duty side doors
    • Core hydraulic lines and controls with standard main valves on upper structures
    • Door locks, cap locks and Caterpillar one key security system
    • Automatic swing parking brake
    • Travel alarm
    • Counterweight with lifting eye
    • Right front corner guard
  • 320d Fm General Forestry Arrangement Also Includes:
    • Forestry cab, hydraulic tilt 18" riser
    • High-wide undercarriage or heavy-duty long undercarriage
    • Heavy-Duty recoil springs
    • Heavy-Duty track roller frame
    • Heavy-Duty travel motor covers
    • Heavy-Duty swivel guard
    • Forestry Heavy-Duty upper frame with catwalk
    • Heavy-Duty bottom guard
    • Heavy-Duty side doors
    • Right front corner guard
    • Travel alarm
  • 320d Fm Log Loader Arrangement Also Includes:
    • Forestry cab
    • Hydraulic tilt 48" riser
    • High-wide undercarriage
    • Heavy-Duty recoil springs
    • Heavy-Duty track roller frame
    • Heavy-Duty travel motor covers
    • Grapple/rotator hydraulic arrangement
    • Heavy-Duty swivel guard
    • Forestry Heavy-Duty upper frame with catwalk
    • Heavy-Duty bottom guard
    • Heavy-Duty side doors
    • Right front corner guard
    • Travel alarm

Optional Equipment

  • Front Linkage: General Forestry
    • Reach Boom 5.7m (18 ft 8 in)
    • Reach Stick 2.9m (9 ft 6 in)
    • Reach Stick 2.9m (9 ft 6 in), Harvester
    • Bucket Linkage CB1 Family
    • Boom Lowering Control Device
  • Hydraulic Packages: General Forestry
    • Rotating Grapple
    • Harvesting Head
    • Thuumb
  • Auxiliary Hydraulic Lines: General Forestry
    • Auxiliary lines HP & MP, Reach Boom
    • Auxiliary lines HP & MP, Reach Stick
  • Engine/power Train
    • Auto Reverse Fan
    • Prefilter, air
    • Cold Weather Starting Aid
    • Extended life Cooling with 50% Concentration -34°C (-30°F)
  • Undercarriage (track Shoes)
    • 600 mm (24 in) Double Grouser Shoes with Trap Holes
    • 700 mm (28 in) Heavy-Duty Double Grouser Shoes with Trap Holes
    • 700 mm (28 in) Heavy-Duty Triple Grouser Shoes with Trap Holes
    • 800 mm (32 in) Heavy-Duty Triple Grouser Shoes with Trap Holes (For HW U/C only)
  • Electrical
    • Product link (PL 321 SR)
    • Maintenance Service lights for Pump and Battery Comparment
    • Working HID Lights for Boom
  • General Optional Equipment
    • Auxiliary Pump Driver (for additional hydraulic pump)
    • Adapter boom foot (for harvester configuration
    • Pump, Electrical Refueling
    • Pump, Vacuum (Hydrualic)
    • Rubber Guard for Boom Foot
    • Right Front Corner Fuel Tank(additional 409 L (108 gal))
    • Heavy Counterweight (Additional 1970 kg - (4,344 lb)) For General Forestry (Standard on Log Loader)
  • Front Linkage: Log Loader
    • Under/Under Boom/Stick/Heel Linkage
    • Stick Cylinder Guard
    • Heel, Log Loader
  • For General Forestry
    • Ground Saw Slasher