Model Spotlight

Case 1550 Crawler Dozer: Specs, Parts & Common Issues

The Case 1550 is the heavy-class Case crawler dozer positioned between the 1450 family and the larger 1650 / 1850 classes - Case A504BDT inline six-cylinder turbocharged diesel, power shift transmission with torque converter, and a heavy-duty undercarriage suited to serious commercial dirt work and large-acreage land-clearing. The 1550 expanded the heavy-class Case dozer offering with more pushing power and operating weight than the 1450B without stepping all the way up to the 1850.

Broken Tractor Editorial Team• Updated May 2026• 10 min read

The Case 1550 Crawler Dozer is the heavy-class Case crawler dozer in the gap between the 1450 family and the larger 1650 / 1850 classes. The 1550 sits in the heavy-commercial dozer range - larger and heavier than the 1450B, with more pushing power and a wider blade, but easier to transport and lower-cost-to-operate than the 1850-class machines. The 1550 inherits the proven Case A504BDT turbocharged inline six-cylinder diesel and power shift transmission with torque converter from the 1450 family.

The 1550 fills the heavy-class gap between 1450 and 1850 The 1550 sits between the 1450/1450B (heavy-class) and the 1850-class machines (largest in the original Case dozer line). For operators who need more pushing power than a 1450B but want to avoid the size, fuel burn, and transport complexity of an 1850, the 1550 fills a specific niche. The Case A504BDT engine and power shift drivetrain are shared with the 1450 family, simplifying parts sourcing for shops already running 1450/1450B equipment.

At-a-glance specifications

Case 1550 - factory specifications

Engine: Case A504BDT inline 6-cylinder turbocharged diesel
Displacement: 504 cu in (~8.3 L)
Power: ~175 - 190 horsepower flywheel (configuration dependent)
Transmission: Power shift with torque converter
Hydraulics: Open-center implement circuit, heavy-class
Variants: Standard, LGP (Low Ground Pressure)
Operating weight: ~42,000 - 46,000 lb depending on configuration
Blade: 6-way bulldozer blade - angle and tilt blade options, larger than 1450B blade
Serial plate location: Right side of operator's platform / chassis frame

How the 1550 differs from the 1450B below

Larger chassis and heavier operating weight - approximately 4,000 lb heavier than a comparable 1450B, translating to more pushing power under load.
Wider blade - wider 6-way bulldozer blade for greater material capacity per pass.
Higher engine output - refinements to the Case A504BDT bump power output relative to the 1450B base configuration.
Heavier-duty undercarriage - larger sprockets, heavier track frame, wider track pad options.
Same engine and transmission family - Case A504BDT and power shift continue from the 1450/1450B for parts continuity.

How the 1550 differs from the 1850 above

Smaller chassis and lower operating weight - easier to transport on a standard lowboy trailer.
Lower engine displacement and power - 504 cubic inches vs. larger displacement on the 1850.
Lower fuel burn - more economical to operate over a long workday.
Shorter transport length - easier permitting and over-the-road movement.

Case A504BDT inline 6-cylinder turbocharged engine

The 1550 uses the Case A504BDT inline six-cylinder turbocharged diesel - same engine family as the 1450 / 1450B / 1455B. 504 cubic inches of displacement (approximately 8.3 liters), with turbocharging. Approximately 175-190 horsepower flywheel in 1550-class trim.

The A504 engine ecosystem is broad - accessory parts (water pump, alternator, starter, oil pump) share with other heavy Case industrial 6-cyl applications. Injection pump and injector service is well-documented. Turbocharger service is a routine wear item.

Browse the Case Dozer Parts hub for current 1550 engine service kits.

Power shift transmission with torque converter

The 1550 uses the same power shift with torque converter family as the 1450/1450B. Clutchless gear changes under load, multiple forward and reverse speeds, torque converter providing smooth power transfer. Routine service items: shift solenoids and pressure switches, clutch packs, torque converter, transmission oil cooler, transmission filter.

Undercarriage

The 1550 undercarriage is heavier-duty than the 1450/1450B but lighter than the 1850-class. Sprocket bolt patterns, idler geometries, and master pin dimensions are 1550-class specific - confirm by part number against your serial.

Browse the Case Dozer Parts hub for current 1550 undercarriage availability.

Blade system and hydraulics

The 1550 ships with a 6-way bulldozer blade - wider and taller than the 1450B's blade. Angle and tilt control are hydraulically actuated. Blade cylinders, blade-carrier slider blocks, and cutting edges are routine service items.

Hydraulic implement-circuit pressure is moderate by modern standards - open-center hydraulic systems were standard in this era. Seal kit availability for the blade cylinders is generally good.

Variants: Standard, LGP

The 1550 shipped in two primary track configurations:

Standard - standard-width track, balanced general heavy-class dozing.
LGP (Low Ground Pressure) - wider grouser pads and extended track frame for soft-ground / wetlands / agricultural-soil work.

Track configuration affects undercarriage and frame parts. Confirm Standard vs. LGP by serial before ordering.

Common 1550 service items

Engine accessory aging

Water pump, alternator, starter, injection pump, and turbocharger on the A504BDT are routinely rebuilt or replaced over the engine's service life.

Turbocharger wear

The A504BDT turbocharger is a routine wear item. Symptoms: blue smoke at startup or under load, oil consumption, audible whine outside the normal range, visible shaft play.

Power shift / torque converter service

Shift solenoid failure, clutch pack wear, torque converter degradation, transmission oil cooler service. The transmission filter and fluid should be on a scheduled service interval.

Hydraulic seal failure

Blade cylinder seal failures are common at production-run age. Cylinder rod chrome corrosion and seal weep are typical symptoms.

Undercarriage replacement cycles

Heavy-class undercarriage components have measurable wear lives. Modern aftermarket undercarriage is available for the 1550.

Operator station and ROPS

Cab and canopy hardware, seat cushion replacement, and floorboard wear are typical aging-machine issues. ROPS structural integrity should be verified before resale.

Wiring and electrical

Production-run-age wiring harnesses can develop intermittent issues from connector corrosion and insulation aging.

Parts and cross-fit components for the Case 1550

Component area	What to look for	Notes
Sprockets & segments	Heavy-class track sprocket assemblies, bolt-on segments	1550-class specific - confirm by serial.
Idlers & rollers	Heavy-class front idler assemblies, top and bottom roller sets	1550-class undercarriage components.
Track recoil & adjusters	Recoil spring, adjuster yoke, chrome rod	Confirm by serial.
Master pins	Heavy-class track master pin and bushing	Master pins are 1550-class specific.
Cutting edges & end bits	Standard and severe-duty cutting edges, end bits	Aftermarket cutting edges widely available for the 1550's heavy-class blade.
Blade cylinder seal kits	Angle, tilt, lift cylinder seal kits	Confirm cylinder dimensions before ordering.
Engine accessory parts	Water pump, alternator, starter, fuel injection	Case A504BDT accessories share parts with other heavy Case industrial 6-cyl applications.
Turbocharger (A504BDT)	Heavy-class turbocharger	Routine wear item - aftermarket rebuild and replacement available.
Radiators & cooling	Radiator cores, fan belts, hose sets	Heavy-class cooling system.
Filter service kits	Engine oil, fuel, air, hydraulic filter sets	Filter kits packaged by application speed routine service.
Power shift transmission parts	Shift solenoids, clutch packs, oil cooler, torque converter	Cross-fit with the 1450/1450B power shift family.
Operator seat	Universal industrial seat with mount kit	Universal Case industrial seats fit the 1550 operator station.

For 1550 parts inventory and cross-fit confirmation, browse the Case Dozer Parts hub or contact our parts desk directly.

Working on a Case 1550?

The 1550 sits between the 1450B and the 1850 - heavy-class chassis with the proven Case A504BDT turbocharged six-cylinder and power shift drivetrain. Our specialists can verify Standard vs. LGP fitment by serial.

Mon - Fri, 7:00 AM - 5:00 PM CT

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Why the 1550 is still in service

The 1550 fills a productive heavy-class niche - more pushing power than a 1450B but easier to transport and less expensive to operate than an 1850. The Case A504BDT turbocharged engine is well-documented, and the power shift drivetrain with torque converter is simpler to troubleshoot in the field than modern hydrostatic systems. For commercial dirt work, major road maintenance, and large-acreage land-clearing where the 1450B is just slightly underpowered, the 1550 is the right machine.