Used Caterpillar D7G2 Bulldozer

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It appears there may be a slight mix-up in the model name, as Caterpillar does not produce a “D7G2 Grader.” The Caterpillar D7G Series II (often abbreviated D7G2 or D7G S2) is actually a track-type tractor (bulldozer), not a motor grader. Below is a detailed English introduction to this classic bulldozer model.

Caterpillar D7G Series II Track-Type Tractor

Overview

The Caterpillar D7G Series II is a medium-sized crawler bulldozer that succeeded the original D7G. Built for heavy earthmoving, land clearing, grading, ripping, and dozing applications, it became renowned for its rugged reliability, simple maintenance, and strong performance. The “Series II” upgrade introduced refinements to the powertrain, undercarriage, and operator station while retaining the proven Caterpillar 3306 engine.

Engine

Model: Caterpillar 3306 DITA (Direct Injection, Turbocharged, Aftercooled)
Type: 4-stroke, inline-6 cylinder diesel
Displacement: 10.5 litres (638 cubic inches)
Bore × Stroke: 121 mm × 152 mm (4.75 in × 6.0 in)
Flywheel Power: 149 kW (200 hp) @ 2,000 rpm
Net Power (SAE J1349): Approximately 145 kW (195 hp) under typical operating conditions
Cooling System: Jacket water with thermostatically controlled fan
Fuel System: Direct injection with individual pump-and-nozzle assemblies; reliable and easy to service
Air Cleaner: Dry-type radial seal with primary and secondary elements and an automatic dust ejector

The 3306 engine is widely regarded as one of Caterpillar’s most dependable powerplants. Its torque rise provides excellent lugging ability when pushing heavy loads, and the aftercooled turbocharging ensures good fuel efficiency and high-altitude performance.

Transmission & Drivetrain

Transmission Type: Caterpillar planetary powershift, full power-shift
Speeds: 3 forward / 3 reverse
Torque Converter: Single-stage, high-capacity torque converter matched to the engine
Transmission Control: Single-lever twist-grip selector for easy speed and direction changes
Final Drives: Double-reduction spur gear final drives with segmented sprockets for long life
Steering: Multiple-disc oil-cooled steering clutches and contracting band brakes; hand-operated levers with boosted assistance (optional pedal steering on some configurations)

The powershift transmission allows on-the-go shifting under load without losing momentum, improving productivity in cycle-duty operations.

Undercarriage

Track Gauge: 1,880 mm (74 in) standard
Track on Ground: 2,540 mm (100 in) – varies with configuration
Standard Track Shoes: 560 mm (22 in) single grouser; options up to 760 mm (30 in) for low ground pressure (LGP) versions
Rollers: 6 track rollers per side, 2 carrier rollers per side
Idlers: Heavy-duty cast idlers with lifetime-lubricated bearings
Track Links: Sealed and lubricated track (SALT) – pins and bushings are internally lubricated, dramatically reducing internal wear and extending track life
Ground Pressure (Standard): ~58 kPa (8.4 psi) depending on shoe width

The suspended undercarriage uses a semi-rigid equalizer bar to improve ride quality and maintain ground contact over uneven terrain.

Hydraulic System

Implement Pump: Gear-type pump driven from the engine
System Capacity: Adequate flow for simultaneous tilt and lift functions
Control Valve: Pilot-operated or manual control with single-lever blade control and optional ripper control
Blade Lift Cylinders: Two double-acting cylinders for strong breakout force
Tilt Cylinder: Single or dual tilt options depending on blade type
Ripper (Optional): Available with a parallelogram or fixed-shank ripper using an additional control lever

Operator Station

The D7G Series II introduced improvements to operator comfort and safety:

ROPS (Roll-Over Protective Structure): Open canopy or fully enclosed cab with optional heater, defroster, and air conditioning
Seat: Adjustable fabric or air-suspension seat
Controls: Ergonomically laid out; steering levers, transmission lever, and blade controls within easy reach
Instrumentation: Gauges for engine coolant temperature, hydraulic oil temperature, fuel level, and torque converter temperature; warning lights for low oil pressure and high coolant temperature
Visibility: Tapered hood and good sight lines to the blade corners and ripper

Blade Options

The machine was commonly equipped with several types of bulldozer blades:

Straight (S) Blade: Designed for heavy dozing and pushing; high capacity and strength
Universal (U) Blade: For moving large volumes of light materials over longer distances
Semi-Universal (SU) Blade: A versatile combination of penetration and capacity
Angle Blade: Manually adjustable to angle left or right for side-casting and grading (though it’s not a motor grader, it could perform light grading tasks)

Blade capacity for a straight blade on the D7G typically ranged from 5.2 to 6.5 cubic meters (6.8 to 8.5 cubic yards) heaped.

Weights & Dimensions (approximate)

Operating Weight: 20,200 – 21,800 kg (44,500 – 48,000 lb) depending on configuration
Length (with S-blade): ~5,080 mm (200 in)
Width (over tracks): ~2,400 mm (94 in) with standard shoes
Height (to top of ROPS): ~3,150 mm (124 in)
Ground Clearance: ~390 mm (15.3 in)

Key Features & Benefits

Proven Powertrain: The 3306 DITA engine and powershift transmission became legendary for their durability and ease of rebuilding.
Ease of Maintenance: Grouped service points, easily removable side panels, spin-on filters, and a modular powertrain design allow major components (engine, transmission, final drives) to be exchanged quickly.
Fuel Efficiency: The direct injection system and torque converter match provide competitive fuel consumption for its size class.
Versatility: Compatible with a wide range of attachments including straight, U, and angle blades; single- or multi-shank rippers; winches; and drawbars for towed scrapers.
SALT Undercarriage: Sealed and lubricated track dramatically reduces hourly undercarriage costs compared to dry-pin track chains.
Operator Comfort: The Series II cab offered reduced noise levels and better climate control, making long shifts less fatiguing.

Applications

Construction: Site preparation, backfilling, embankment building
Mining: Overburden stripping, stockpile dozing
Forestry: Land clearing, firebreak construction (often with special guarding packages)
Agriculture: Terraforming, drainage channel shaping, orchard clearing
Landfill: Spreading and compacting waste (with landfill-specific guarding)

Legacy

The D7G Series II bridged the gap between the older D7G and the more technologically advanced D7H and D7R Series. Even decades after production ended, many D7G2s remain in service worldwide due to their mechanical simplicity and the vast availability of aftermarket parts. They are prized by smaller contractors and those working in remote areas where electronic controls are not desirable.

If you were actually looking for a Caterpillar motor grader (such as the 12G, 14G, or newer M Series), please let me know, and I can provide a detailed introduction to one of those models.

Non flooded

No accident

Original product

Used Caterpillar D7G2 Bulldozer

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