Model Spotlight

Case 450B Crawler Dozer: Specs, Parts & Common Issues

Produced 1978 – 1983, the Case 450B is a dependable mid-size crawler dozer that paired Case's proven 207-cubic-inch four-cylinder diesel with a 4-speed power shift transmission and torque converter. 53 net horsepower, 11,400-pound operating weight, 21 gpm hydraulic flow at 1,650 psi — a classic small-class dozer that remains popular for grading, land clearing, and light industrial work today.

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

The Case 450B Crawler Dozer is the B-generation successor to the original Case 450 (a 1965–1977 machine), produced from 1978 through 1983 at Case's Burlington, Iowa works. It carried forward the Case 207 four-cylinder direct-injection diesel — a 3.4-liter naturally aspirated engine — paired with a 4-speed power shift transmission and torque converter, which was the major drivetrain upgrade over the predecessor 450's mechanical transmission. Output is rated at 53 horsepower net at the flywheel, 11,400 pounds operating weight in standard configuration, and a 21 gpm hydraulic system running at 1,650 psi.

For owners maintaining a Case 450B today, the parts ecosystem is deep — the cross-fit network covers the predecessor 450 and successor 450C, 450D, 450E, and the parallel 550 / 550E / 550G dozers. The 450TK torque converter rebuild kit is a routine high-volume service item, and the D31142 bushing has one of the broadest cross-fit footprints of any dozer-class part we carry.

At-a-glance specifications

The Case 207 diesel engine

The Case 207 is a 207 cubic inch (3.4 L) four-cylinder direct-injection diesel used across several Case industrial and agricultural machines of the era — most notably the Case 580C and 580D backhoe loaders, several Case 4500-series forklifts, and the 450B / 455B / 450C dozer family. That broad cross-application keeps engine internals well-supported in the aftermarket. For full engine rebuilds, the CS-207-ENG complete rebuilt Case 207 diesel engine is the verified drop-in replacement. For in-frame work, the CS207ERK non-turbo overhaul kit by Reliance covers pistons, rings, bearings, gaskets, and the supporting hardware needed for a complete rebuild.

For individual engine internals, the A144011 crankshaft and 5A50975 connecting rod bearing set are the most commonly ordered components when the bottom end is being refreshed.

Power shift transmission and torque converter

The 450B's 4-speed power shift transmission with torque converter was Case's mid-size-dozer drivetrain solution from the late 1970s through the early 1980s. The power shift architecture lets the operator change direction under load without coordinating a clutch — a major productivity improvement over the predecessor 450's mechanical transmission. The torque converter provides the mechanical buffer between engine and transmission, smoothing out load impulses and protecting the gearbox during heavy dozing work.

The torque converter is the most-replaced major drivetrain component on the 450B. The 450TK rebuild kit handles in-place rebuild. For machines with the torque converter beyond piecemeal rebuild, the R42395R rebuilt torque converter is the drop-in replacement. The companion D52483 flex plate connects the engine flywheel to the converter and is a common companion replacement when the converter comes out.

Hydraulic system

21 gpm of hydraulic flow at 1,650 psi is modest by modern dozer standards but well-matched to the 53 HP engine and the 450B's intended work. Blade angle, tilt, and ripper functions are all hydraulically actuated. The 140146A1 blade angle cylinder and G101228 blade tilt cylinder are the standard hydraulic replacements; if the machine is equipped with a rear ripper, the G101230 ripper cylinder (which cross-fits 450B through 550H) is the verified replacement.

Undercarriage and tracks

The 450B undercarriage is a steel grouser-pad track running on standard rollers, idlers, and sprockets. The R53591 front track idler kit covers both standard 450B and the 450B LGP variant. The 389390A1 track adjuster yoke (cross-fits 450B through 550H) and the R51909 made-in-USA track adjuster are the standard adjuster service items. The 187916A2 left-hand recoil spring assembly (cross-fits Case 450 through 550G) handles the recoil function when track tension hits an obstacle.

For final drive bearing replacement, the G102659-Kit carrier bearing kit is the verified rebuild kit specific to the 450 and 450B. The D35270 idler shaft covers 450, 450B, and 455B applications.

LGP variant

The Case 450B LGP (Low Ground Pressure) is a wider-track variant of the standard 450B, designed for soft-ground applications like wetlands work, agricultural field grading, and golf course / landscape projects. The LGP shares its engine, transmission, hydraulics, and most undercarriage components with the standard 450B; the differences are in track width, frame width, and ground pressure rating. The R53591 front idler kit is explicitly labeled for both 450B and 450B LGP configurations.

Cooling system

Two radiator options exist depending on the build year and configuration: the R39432 Young-style radiator with bottom tank oil cooler ports and the R41126 Modine-style radiator with face-side oil cooler ports. Confirm which version your 450B has by inspecting the cooler port location on the original radiator before ordering — they're not interchangeable.

Parts we carry

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

For a comprehensive Case 450B parts search, browse the Case & IH Dozer Specs and Information hub or contact our parts team for serial-number-specific verification.

Common issues and what to expect

Torque converter degradation

By far the most common 450B drivetrain issue. Symptoms: engine bogging under load, slow takeoff from a stop, abnormal heat in the bell housing area, slipping under hard pushing. The 450TK rebuild kit covers in-place rebuild; the R42395R reman converter is the drop-in replacement when piecemeal rebuild isn't cost-effective.

Case 207 engine wear

Common items on 40-plus-year-old Case 207 engines: head gasket failure (typically front of block), valve seat recession on heavy-duty service, injection pump wear (Roosa Master / Stanadyne rotary pump on most builds), and water pump shaft bearing wear. Engine parts are widely available through both Case and the broader aftermarket; the CS207ERK overhaul kit covers most rebuild needs.

Cooling system corrosion

Original radiator cores corrode internally over 40-plus years. Replace with either the R39432 Young or R41126 Modine radiator depending on original configuration. Inspect cooling hoses and water pump at the same time.

Track adjuster and recoil spring wear

The track recoil spring fatigues over decades. Symptoms: tracks jump under load, audible "slap" during direction reversals, or visible track slack that doesn't adjust out. The 187916A2 recoil spring assembly is the verified replacement. The 389390A1 adjuster yoke and R51909 adjuster handle the rest of the adjuster system.

Front idler wear

Front idler wear shows up as track wandering and uneven wear on the grouser pads. The R53591 front idler kit includes the idler wheel, shaft, blocks, and supporting hardware for both standard 450B and LGP configurations.

Final drive seal weeps

The final drive seal goes after 40 years of service. Symptoms: gear oil weeping at the sprocket hub, audible bearing rumble. The G102659-Kit carrier bearing kit covers the rebuild components.

Hydraulic cylinder seal failure

Blade angle, blade tilt, and ripper cylinder seals all degrade with age. Contact our parts team for current seal kit options — the 140146A1 angle cylinder, G101228 tilt cylinder, and G101230 ripper cylinder are all verified fitments for the 450B.

Operator station wear

Original seat cushions and arm rests wear after decades of operator-station service. The PV810 cushion set or the complete R48423 seat are the verified replacements.

Where the 450B sits in the Case dozer family

The 450B is the small-class Case crawler dozer for the late 1970s and early 1980s, sitting between the smaller Case 350 and the larger Case 550 in the lineup. After the 450B came the 450C (1989–1998) with the larger Case 4-390 Cummins-derived 3.9L engine and a refined operator station. Between the original 450 (1965–1977) and the 450C, the 450B represents the bridge generation that introduced power shift to Case's small-class dozer line.