Mini Excavator 308 CR
Engine
Engine Model 4M40E1 .
Gross Power 41 kW 55 hp .
Flywheel Power 41 kW 54 hp .
Drive .
Max. Drawbar Pull 57 kN 12,810 lb .
Operating Weight 8040 kg 17,730 lb .
Weights .
• Equipped with 2470 mm (8'1") blade, one-piece boom
2210 mm (7'3") stick, 600 mm (24") shoes, and 600 mm.
(24") bucket.
Compact Radius
1) Front Swing From Center |
1665 mm (5 ft 6 in) stick - 1660 mm (5 ft 5 in) |
2210 mm (7 ft 3 in) stick - 2180 mm (7 ft 2 in) |
2) Rear Swing From Center |
1290 mm (4 ft 3 in) |
3) Overhang |
450 mm (18 in) shoes - 130 mm (5 in) |
600 mm (24 in) shoes - 55 mm (2 in) |
4) Width |
1665 mm (5 ft 6 in) Stick - 2950 mm (9 ft 8 in) |
2210 mm (7 ft 3 in) Stick - 3470 mm (11 ft 5 in) |
Compact Radius Design. The 308C CR is a compact radius version of the 307C. It is designed to work in a 2850 mm.(9 ft 8 in) wide area.
Shorter Tail Swing Radius. A shorter tail swing radius makes the 308C CReasier to operate against walls and in
other tight areas, reducing the risk of damage to the rear of the machine during operation.
Flexibility in Tight Quarters. The shorter tail measurement allows the excavator to work productively in urban construction, on logging roads and other spacerestricted sites.
Undercarriage
ENGINE
4M40-E1 Engine. The Mitsubishi 4M40-E1 engine was developed specifically for construction equipment. It features a long-stroke piston movement forhigh torque at medium to low speeds, excellent fuel efficiency and low
sound levels and vibration.
Low Fuel Consumption. The engine offers low fuel consumption, improved thermal efficiency and reduced resistance between pistons and liners.
Cylinder Block and Head. The cylinder block is made of cast iron for improved wear resistance. The upper part is laserhardened to reduce oil consumption, increase wear resistance and minimize piston ring scuffing. Aluminum alloy cylinder heads incorporate water directors to ensure efficient cooling.
Pistons and Rings. Heat-resistant aluminum cast alloy pistons featureclearance control struts. A short compression height results in high combustion efficiency and reducedweight. The piston ring set consists of three rings, treated for maximum wear resistance.
Crankshaft and Connecting Rod.The surface of the crankshaft journals and pins are induction-hardened to ensure high reliability. The forged connecting rods are made of a hightensile strength steel alloy.
Cooling System. A large-diameter fan and full-length, water-cooled cylinders,combined with excellent thermal efficiency, help prevent overheating. The result is longer engine life and the ability to operate at high temperatures and under heavy loads. A mixed flow fan design provides high cooling efficiency. The core radiator is equipped with waved fins to prevent clogging.
Lubrication System. The system utilizes an external gear-type, high-efficiency oil pump. The large oil filter is composed of a main filter and a bypass filter,designed for high performance.
Starting System. The standard 308C CR has a 3.2 kW capacity starting motor, mounted at the right of the engine, and two Cat 100-AH capacity batteries. In this configuration, the machine can be started at -32ºC (-25ºF) with glow plugs.5
HYDRAULIC
HYDRAULIC
Precise Control. Hydraulics deliversmooth changes in speed and outstandingoverall control.
Pilot System. Increased pilot hydraulicpressure provides better control to thefront linkage, swing and travel operations.
Component Layout. The 308C CRhydraulic system was designed to provide a high level of efficiency. With all major components located close together, shorter tubes and lines are needed,resulting in less friction loss in the lines and reduced pressure drops.
Flow Control System. Pump flow decreases when controls are in neutral for reduced fuel consumption and sound levels.
Stick Regeneration Circuit. Saves energy while the stick is in use, providing shorter cycle times and lower operating costs.
Boom Drift Reducing Valve. This valvereduces the natural drift of the boom, so lifted material will remain suspended for long periods with virtually no drift.
Auxiliary Hydraulic Valve. The auxiliary hydraulic valve is standard on the 308C CR for use with optionalhydraulic circuits.
Stackable Valves. One stackable valve can be used in combination with the main control valve, allowing additional tools to be added.
Auxiliary Hydraulic Arrangements. For maximum flexibility, three arrangements are available on the 308C CR: single function for a dedicated hammer, doublefunction for a thumb or a combined function circuit.
Hydraulic Cylinder Snubbers. Snubbersare located at the rod-end of the boomcylinders and both ends of the stick cylinders to cushion shocks while reducing sound levels and extendingcylinder life.
Front Linkage Attachments. Allows the use of one boom, two sticks and four buckets. Using these combinationsmakes the excavator productive in a wide range of applications.
One-Piece Boom. The one-piece boom features a fabricated box-section design. Robotic welding and high-tensile strength steel on upper, lower and side plates provide high durability and consistency.
Sticks. Two stick attachments are available: a long stick to maximizereach or a medium stick for the most versatile front linkage. Both sticks use a box-section design made of high tensile-strength steel and a buffer plate.
Linkage Bearings. A self-lubricated, sintered bearing greatly extends the greasing interval on front linkage pins by reducing pin friction. Greasing intervals on the bucket swing pin connection are also extended using a mesh bearing design.
Linkage Pins. Linkage pins are used with high-stress parts such as at the boom foot and boom cylinders. They feature a thick chrome finish to maximize durability. The 308C CR pin diameters are the same as on the 307C,except for boom cylinder-frame pin size.
Buckets. High-tensile-strength steel is used in high-stress areas for excellent wear and shock resistance. The side
Bucket-Flop Adjustment Mechanism.
Allows the operator or service person to reduce the side play at the bucket to stick-nose connection. This attachment
Undercarriage
Undercarriage Design. The 308C CR uses a standard undercarriage with the same basic design as the 307C, ensuring high reliability.
Grease-Lubricated Track. Greaselubricated seals protect the track link and provide longer wear life by helping
to keep dirt and debris from entering the pin and bushing joint.
Roller Lubrication. All rollers, sprockets and idler joints are closed with floating seals. Lubricating oil from the seals prevents water and dirt from entering. The seals also make lubrication maintenance-free.
Master Pin. The standard master pin is the split-pin type, which makes track attachment and removal easier. OPERATION STATION
Cab Design. An enlarged cab with curvedstyling gives the operator a comfortable,spacious working environment and improved visibility.
Seat. The low-back seat slides forward and backward independent of the consoles, so it can be adjusted to the operator’s comfort level.
Sliding Door. The cab door slides alongside the cab and takes less space to open and close than a hinged door.
This unique design allows the operator to easily get in and out of the cab when working against walls on job sites, even when attachments are added.
Consoles. Redesigned consoles feature a simple, functional design. Both consoles have attached adjustable armrests and slide forward and backward.
Monitor. The conveniently located compact monitor displays instrument panel gauges and indicators in an easyto- read and understand format.
Cab Mounts. The cab shell is attached to the frame with viscous rubber cab mounts, which dampen vibrations and
sound levels while enhancing operatorcomfort.
Travel Control Levers. The two travel control levers have a reverse-L shape, making them easier to operate. Lever stroke and force have been adjusted to improve fine control and to prevent jolting during machine impact.
Hydraulic Activation Control Lever.
For added safety, this lever must be in the locked position before the operator can leave the cab. This feature prevents the machine from operating without the operator in the cab.
Climate Control. Fully automatic climate control adjusts temperature and flow.
Windows. Window glass is attached directly to the window frame with adhesive to improve visibility. To protect the operator from falling objects, the upper front window is made of laminated glass. An enlarged skylight with sunshade improves overhead visibility.
Windshield. The front windshield can be opened and closed using a one-touchaction release system and autolock system.
Serviceability
Simplified service and maintenance save you time and money.
Extended Service Intervals. Extended service and maintenance intervals reduce service time and machine availability. Use of oil-free bearing extends front linkage greasing interval
to 1,000 hours, except in bucket area.
Ground-Level Maintenance. For operator convenience, all daily maintenance areas can be easily reached from
ground level.
Fan Guard. Engine radiator fan is completely enclosed by fine wire mesh, reducing the risk of injury.
DT Electrical Connectors. Connectors are water- and vibration-resistant, improving electrical system reliability.
Radiator and Pump Compartment.Opening the engine hood allows easy access to the engine radiator and the oil cooler. A reserve tank and drain cock are attached to the radiator to simplify maintenance.
Air Filter. Cat radial seal provides superior cleaning efficiency.
Engine Inspection. The engine can be accessed from the upper structure or from under the machine. The engine
hood incorporates a gas cylinder-assist mechanism, making the hood easy to open. A steel wall separates the engine
and pump compartments, preventing hydraulic oil from spraying on the engine in the event of a hydraulicline failure.
Engine Maintenance. To make dailyservicing easier, the oil level gauge, oil filter, fuel filter and priming pump are grouped on the left side of the engine.
Fuel Tank. A drain cock is installed at the bottom of the tank, making it easier to remove water and sediment during maintenance.
Fuel-Water Separator. The water separator has a primary fuel filter element and is located in the radiator compartment for easy access from the ground.
Storage Box. The storage box is located at the right front of the upper structureand can be locked. Tools and other repair equipment can be stored in this space.
