Model Spotlight

Case 550 Crawler Dozer: Specs, Parts & Common Issues

Produced 1974 – 1988, the Case 550 is a versatile mid-class crawler dozer with a 14-year production run — Case G188D 188 cubic inch / 3.1 liter four-cylinder diesel, 58 net horsepower, choice of 4-speed mechanical shuttle or power shuttle transmission, and a heavy-duty undercarriage. The original 550 launched the Case 550 nameplate that continued through 550E, 550G, and 550H generations.

BT

Broken Tractor Editorial Team• Updated May 2026• 11 min read

The Case 550 Crawler Dozer is the launch machine of Case’s 550 nameplate, produced from 1974 through 1988 — a 14-year run that makes it one of the longest-production Case dozer models. Power comes from the Case G188D — a 188 cubic inch (3.1 L) four-cylinder direct-injection diesel rated at 58 net horsepower at 2,000 rpm, with 162 lb-ft of peak torque at 1,200 rpm. Two transmission options were offered: a 4-speed mechanical shuttle or a 4-speed power shuttle, with the power shuttle becoming more common in later production.

For owners maintaining a 550 today, the most important production-related fact is the serial break at JAK0013968. Case changed several drivetrain components mid-production — most notably the sprocket. Before JAK0013968, the 550 uses one sprocket configuration; after JAK0013968, it uses the same long-track sprocket carried forward to the 550E, 550G, and 550H. Confirm your serial number before ordering sprockets or anything tied to the late-production drivetrain. The R57298 sprocket is explicitly labeled for 550 machines after JAK0013968, plus 550E, 550G, and 550H.

At-a-glance specifications

The Case G188D engine

The Case G188D is one of Case’s most-used industrial diesel engines — a 188 cubic inch (3.1 L) four-cylinder direct-injection diesel that powered the 550 dozer plus a wide range of Case backhoe loaders (480CK, 480B, 480D, 580CK, 580B), the Case 350 dozer, and several Case forklifts and wheel loaders. That broad application base keeps engine internals well-supported in the aftermarket — pistons, rings, bearings, head gasket sets, and fuel system components all cross through the Case 188 service ecosystem.

Common service items on a 40-plus-year-old G188D: head gasket failure (front of block most common), valve seat recession, injection pump wear (Roosa Master / Stanadyne rotary pump), water pump shaft bearing wear, and lift pump diaphragm degradation. The engine is mechanically simple and well-documented — well within reach of an owner-mechanic with the right service manual.

Transmission: mechanical shuttle vs. power shuttle

The 550 was factory-available with two transmissions:

• 4-speed mechanical shuttle — operator changes direction by working a foot clutch and column-mounted shuttle lever. Mechanically simpler, fewer hydraulic components, but slower direction changes during dozing work where rapid F/R cycling is common.
• 4-speed power shuttle — hydraulically actuated direction changes without working the clutch. Productivity advantage during heavy dozing. More hydraulic components to maintain, but operator fatigue significantly reduced.

The power shuttle became more common in later production. Confirm which transmission your 550 has before ordering drivetrain-specific parts — clutch, shuttle valve, and torque converter components differ between configurations.

Undercarriage and tracks

The 550’s steel-grouser undercarriage is a known-durable design that runs on a recoil-tensioned track adjuster. The R57366 master pin breaks the track for service and is a one-time-use consumable; budget a fresh master pin every time the track is split.

Track shoe bolt kits are configuration-dependent: the CA875BK kit fits 550 and 650 dozer track shoes; the CA408BK kit fits 450 and 550 dozer applications. Confirm bolt size before ordering.

For sprocket replacement, the R57298 long-track sprocket covers 550 (after JAK0013968), 550E, 550G, and 550H. Pre-JAK0013968 550 sprockets are not in current stock and require separate sourcing.

The AT36391 track adjuster rod has remarkable cross-fit — covers 450, 450B, 450C, 450D, 450E, 550, 550A, and 550B dozers on 5-roller undercarriage configurations. The 187916A2 left-hand recoil spring assembly covers nearly the entire 450 and 550 family (450 through 550G).

Hydraulic system

13.5 gpm at 2,100 psi is the 550’s hydraulic baseline — modest flow but solid pressure for the blade work the machine is designed to do. The 1543250C1 blade lift cylinder seal kit (Bulldog / Hercules, made in USA) covers the blade cylinder rebuild — cross-fits 450B, 450C, and 550 on 6-way blade configurations. The G101230 hydraulic ripper cylinder (cross-fits 450B through 550H) covers ripper-equipped 550 machines.

Cooling and exhaust

The A172489 muffler with spark arrester is the non-turbo exhaust component for the 550 — cross-fits 450C, 455C, 550, 550E, and 550G. Required for any 550 operating in fire-restricted areas (national forests, certain agricultural settings).

The R48058 left-hand engine side shield covers 450C, 550, 550G dozers and the 455C crawler loader.

Operator station

The R48423 replacement seat covers 450B, 450C, 455C crawler loader, and the 550 dozer — broad cross-fit makes seat replacement straightforward.

Parts we carry

The parts table below covers the top routine-service and cross-fit parts for this model.

For a comprehensive Case 550 parts inventory, browse the Case Dozer Parts hub.

Common issues and what to expect

Hydraulic leaks

Blade cylinder seal degradation is the most common hydraulic complaint on 40-plus-year-old 550s. The 1543250C1 blade lift cylinder seal kit covers the blade cylinders. Inspect hoses, fittings, and the steering valve for additional leak sources.

G188D engine wear

Common items on a 40-plus-year-old G188D: head gasket failure, valve seat recession, injection pump wear, water pump shaft bearing wear. The G188D engine ecosystem is large — the same engine powers Case 480CK, 480B, 580CK, 580B backhoes and the Case 350 dozer, so service parts are widely available.

Power shuttle wear (power-shuttle machines)

On 550s equipped with the power shuttle, hydraulically actuated clutch packs wear with age. Symptoms: harsh forward-to-reverse changes, slow direction engagement, slipping under heavy push. The N13044 reman torque converter is the verified drop-in for the power-shuttle drivetrain when piecemeal rebuild isn’t cost-effective.

Steering clutch wear

Symptoms: one track engages slower than the other under load, machine pulls toward one side during straight-line dozing. Steering clutch adjustment is the first diagnostic step; replacement requires splitting the final drive housing.

Final drive seal leaks

Gear oil weeping at the sprocket hub indicates final drive seal failure. This is a known long-term wear pattern across the entire 450/550 family.

Track adjuster and recoil spring wear

The recoil spring fatigues over decades — symptoms include tracks jumping under load and visible track slack that doesn’t adjust out. The 187916A2 recoil spring and AT36391 adjuster rod are the standard service items.

Sprocket and chain elongation

Track chain elongation combined with sprocket chord wear is a known late-life issue. Replace the sprocket and chain together — partial replacement leads to accelerated wear of the new component. The R57298 sprocket is for post-JAK0013968 machines only.

Cooling system corrosion

Original radiator cores corrode internally over decades. Inspect coolant hoses, water pump, and thermostat at major service intervals.

Engine bay sheet metal wear

The R48058 engine side shield is a common replacement item — original shields bend, crack, or rust through after decades of brush-clearing and rough-ground service.

Where the 550 sits in the Case dozer family

The Case 550 is the mid-class crawler dozer for the mid-1970s through the late 1980s, sitting between the smaller Case 450B and the larger 650 in the Case lineup. The 550 launched a long-running nameplate that continued through the 550E (1988–1996), 550G (1996–2001), 550H, and 550H LT (Long Track) variants. Most non-engine service parts in our catalog cross-fit across multiple 550-generation machines — particularly track and undercarriage components.