Used Caterpillar D7H Bulldozer

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It appears there may be a slight mix‑up in terminology. The Caterpillar D7H is a crawler dozer (track‑type tractor), not a motor grader. Caterpillar motor graders are designated by numbers like 120H, 140H, 12H, 14H, etc. The D7H is a medium‑sized bulldozer that was manufactured from the mid‑1980s through the mid‑1990s, and it is widely used for earthmoving, dozing, ripping, and rough grading. Below is a comprehensive overview of the Caterpillar D7H in English, treating it as the dozer it is, while also clarifying its capabilities that sometimes lead to it being used for rough grading tasks.

Overview of the Caterpillar D7H Track‑Type Tractor

The Caterpillar D7H is part of Caterpillar’s long‑running D7 series of crawler tractors, which have been a backbone of construction, mining, forestry, and agricultural operations since the original D7 was introduced in 1938. The “H” series, launched in 1986, represented a significant evolution from the earlier D7G, incorporating a new engine, an improved power‑shift transmission, a more comfortable operator station, and enhanced serviceability. Production of the D7H continued until approximately 1996, when it was succeeded by the D7R.

Though the D7H is fundamentally a bulldozer, it is often employed for rough grading and finishing work when equipped with a properly adjusted blade (typically a straight blade or a semi‑U blade). It is not a motor grader, but its fine control capabilities allow operators to achieve relatively smooth surfaces for haul roads, pads, and backfilling.

Key Specifications

Engine – Caterpillar 3306 DITA (direct injection, turbocharged, aftercooled) six‑cylinder diesel engine.
- Net flywheel power: approximately 200–215 hp (149–160 kW), depending on configuration and rating.
- Displacement: 10.5 litres (638 cubic inches).
- Rated RPM: 2200.
- Fuel injection is direct with a turbocharger and jacket‑water aftercooling for efficiency and durability.
Operating Weight – Typically between 22,000 and 24,000 kg (48,500–53,000 lb), depending on blade type, ripper attachment, and track shoe width.
Transmission – Caterpillar power‑shift, 3 speeds forward and 3 speeds reverse. The transmission uses large‑diameter clutch packs with modulated engagement for smooth shifting and reduced shock loads.
Undercarriage – Sealed and lubricated track (SALT) with heavy‑duty components; track gauge of 2,134 mm (84 in). Standard track shoe width is 560 mm (22 in), with options up to 760 mm (30 in).
Blade Capacity – The standard straight blade has a capacity of approximately 6.5 to 8.0 m³ (8.5–10.5 yd³), depending on the blade model (e.g., 7SU semi‑U blade). The angle blade and universal blade are also available.
Ripper – Optional single‑shank or multi‑shank ripper; penetration force can exceed 16,000 kg (35,000 lb).

Engine and Performance

The 3306 DITA engine was one of Caterpillar’s most reliable powerplants. It featured:

Direct Injection for fast starting and low fuel consumption.
Turbocharging and aftercooling to increase power density and maintain performance at altitude.
Oil‑cooled pistons and hardened cylinder liners for extended life.
A torque rise of about 25%, providing lugging ability when the load increases, reducing the need for downshifting.

The fuel system was mechanical, and the engine met emissions standards of its era. It was known for its simple design, ease of maintenance, and exceptional longevity—many D7H units have clocked over 30,000 operating hours with proper care.

Transmission and Drivetrain

The D7H used a Caterpillar power‑shift transmission with three forward and three reverse gears. Gear selection was managed by a single‑lever console control. The transmission incorporated:

Modulated hydraulic clutch engagement for smooth direction and speed changes without jolting the machine.
Heavy‑duty bevel gear and steering clutches that were oil‑actuated and oil‑cooled, a step forward from the dry steering clutches of earlier models.
Planetary final drives that multiplied torque and reduced stress on the drive shafts, improving reliability.

Steering was achieved via hand‑operated steering clutches and brakes, typical of Caterpillar dozers of that era. The D7H had an advanced hydraulic booster system that reduced lever effort and gave the operator precise control, essential for fine grading.

Hydraulics and Implements

The D7H was equipped with a load‑sensing hydraulic system that provided power to the blade and ripper cylinders only when needed, reducing heat buildup and fuel consumption. The blade could be tilted, angled, or pitched depending on the mount:

Straight blade (S) – excellent for finish grading and spreading.
Semi‑U (SU) blade – combines the penetration of a straight blade with the carrying capacity of a U‑blade, good for large‑scale earthmoving.
Angle blade (A) – can be angled up to 25 degrees left or right, making it useful for ditching, backfilling, and sidecasting material.
Universal blade (U) – large capacity for moving light material over long distances.

The optional ripper (fixed or parallelogram type) allowed the machine to break up compacted soil, rock, and pavement, and to assist in pioneering work. With the ripper down, the D7H could achieve a tractive effort that made it a capable heavy‑duty machine on tough sites.

Operator Environment

Compared to the older D7G, the D7H brought a noticeably improved cab:

ROPS/FOPS canopy or cab – available as an open canopy or an enclosed cab with heating and air conditioning.
Suspended seat with armrests, adjustable for operator weight and height.
Tilt‑steering console that could be adjusted for comfort.
Lower noise levels thanks to better sealing and isolation mounts.
Improved visibility to the blade corners and ripper tip.
Easier‑to‑read gauges and warning lights, including a transmission temperature gauge and torque converter oil temperature monitor.

These features allowed operators to work longer hours with less fatigue, and the precise control response made the D7H suitable for tasks where blade accuracy matters—such as cutting shallow grades for drainage or finishing a pad.

Undercarriage and Durability

The D7H’s undercarriage was built for long life and low maintenance:

Sealed and Lubricated Track (SALT) – pins and bushings were continuously lubricated and sealed to keep out dirt, dramatically increasing pin‑and‑bushing life.
Heavy‑duty track chains with induction‑hardened pins, bushings, and links.
Track adjusters were hydraulic, making it easy to maintain correct track tension.
Oscillating track frames allowed the tracks to follow uneven terrain, providing better traction and a smoother ride.

Track gauge and shoe width could be tailored to the application; wider shoes were used in soft underfoot conditions to reduce ground pressure.

Serviceability

Caterpillar designed the D7H with maintenance in mind:

Engine access was excellent, with hinged side doors and a tilt‑forward hood.
Transmission and hydraulic filters were grouped in a central service bay.
Lubrication points were colour‑coded and centrally located where possible.
Wet‑armour batteries were maintenance‑free (sealed) on later units.
Extended service intervals for engine oil (250 hours) and hydraulic oil (1000 hours) reduced downtime.

Common Applications

The Caterpillar D7H was a versatile machine found on job sites worldwide:

Earthmoving and site development – stripping topsoil, cutting and filling, and bulk material moving.
Road building – pioneering, subgrade preparation, and spreading gravel (often in conjunction with a motor grader for final finish).
Mining and quarrying – stripping overburden, stockpile management, and ripping.
Landfill – compacting and spreading waste, digging trenches.
Forestry – clearing brush, building firebreaks, and log skidding (with appropriate guarding).
Agriculture – land reclamation, drainage, and heavy tillage.

While it is not a grader in the traditional sense, an experienced operator with a straight blade and a tilt cylinder can perform rough grading that sometimes eliminates the need for a dedicated finish grader on small‑scale projects.

Legacy and Transition to D7R

The D7H earned a reputation for being a tough, no‑nonsense tractor that was simple to repair and relatively inexpensive to maintain compared to later electronically‑controlled machines. Its mechanical engine and hydraulic controls meant that troubleshooting and repairs could often be carried out in the field with basic tools. When the D7R arrived in 1996, it brought electronic engine management, differential steering, and more sophisticated operator aids, but many contractors kept their D7Hs in service because of their reliability and lower cost of ownership. Today, the D7H remains a popular model on the used‑equipment market, sought after by owner‑operators and small to mid‑size contractors.

Summary Table (Typical Configuration)

Feature	Specification
Engine Model	Cat 3306 DITA
Net Power	200–215 hp (149–160 kW)
Operating Weight	22,000–24,000 kg
Transmission	Power‑shift, 3F/3R
Undercarriage	Sealed and Lubricated Track (SALT)
Blade Capacity (SU)	~7.5 m³ (9.8 yd³)
Ripper Type	Optional single/multi‑shank
Steering	Clutch‑and‑brake, hydraulic booster
Production Years	1986–1996

If you were actually looking for information on a Caterpillar motor grader, the H‑series models (such as the 120H, 140H, 160H) are the closest match, and I would be happy to provide a detailed overview of those as well. Just let me know!

Non flooded

No accident

Original product

Used Caterpillar D7H Bulldozer

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