1936–1938 Dodge LM-70 / LM-71 Airflow Truck: Gar Wood Streamlined Coachwork

Dodge offered the LM-70 and LM-71 Airflow commercial trucks during the 1936–1938 period with rear-wheel drive, a side-valve six-cylinder engine, and specialized streamlined bodywork most closely associated with Gar Wood Industries. A documented 1938 specification lists Dodge’s 241.5-cubic-inch L-head six at 87 bhp, coupled to a four-speed manual transmission.

These were working commercial vehicles rather than derivatives of the Chrysler Airflow passenger car. Their rounded noses, skirted rear wheels, tightly integrated tanks or cargo bodies, and enclosed cabs applied aerodynamic styling to a conventional heavy truck chassis at a time when most tankers still exposed their radiators, fenders, running boards, and separate body structures.

Best known for their dramatically streamlined tanker bodies and use as rolling corporate advertisements, the LM-series Airflow trucks now rank among the most difficult prewar Dodge commercial vehicles to authenticate and restore correctly.

Quick Facts

The following table separates the core mechanical identity of the LM-70 and LM-71 from details that depended on year, body order, and commercial customer. Exact production totals for these two codes are not consistently documented in surviving published records.

The important distinction is that “Airflow” described the body concept, not an independent unit-body truck platform. Beneath the flowing sheet metal sat recognizably conventional Dodge truck engineering, chosen because a fleet operator needed durability and serviceability more than experimental running gear.

Why the Dodge Airflow Truck Matters

The LM-70 and LM-71 turned a bulk-delivery vehicle into a moving billboard. Their bodywork concealed much of the visual clutter of a conventional truck, wrapping the cab, hood area, fenders, tank, and rear wheels into one continuous composition. That made the vehicle itself part of a petroleum company’s or commercial operator’s public image.

The engineering case was less theatrical. Streamlining could reduce turbulence around the cab and tank, but these trucks worked at speeds where payload, gearing, and route conditions mattered more than maximum velocity. The commercial value came from visibility, cleanliness, and brand recognition. A polished or brightly painted Airflow tanker looked modern even when parked at the curb.

That role also explains why so few remained intact. Commercial trucks were rebuilt, re-bodied, repowered, or scrapped when their revenue-producing life ended. The aerodynamic panels were difficult to repair after collision damage, while a sound chassis could be reused beneath an ordinary cab or freight body. A surviving LM-series frame with credible original streamlined coachwork is therefore far more significant than a conventional period Dodge chassis wearing a newly fabricated interpretation.

Historical Context and Development

Dodge in the Heavy-Truck Market

By the middle of the 1930s, Dodge operated as Chrysler Corporation’s principal truck marque and offered commercial chassis across several weight classes. Chevrolet, Ford, Diamond T, International Harvester, Mack, and White competed for fleet orders, while specialist body builders adapted mass-produced chassis to fuel delivery, parcel work, municipal service, and promotional use.

Dodge’s engineering priorities were conservative and practical: a low-speed six-cylinder engine, a multi-ratio manual gearbox, robust beam axles, leaf springs, and hydraulic brakes. Those components could be serviced through an established dealer network. The Airflow body supplied the visual experiment without forcing an operator to maintain an equally experimental chassis.

Gar Wood Industries and the Streamlined Body

Gar Wood Industries is closely associated with the coachwork fitted to surviving Dodge Airflow trucks. The company’s industrial experience extended beyond the famous Gar Wood racing boats and included truck bodies and hydraulic equipment. On the Dodge, compound-curved panels and the close integration of cab and load body demanded substantially more fabrication than an ordinary tanker assembled from a separate cab, cylindrical tank, and exposed chassis rails.

The front carried a rounded, forward-thrusting profile with a narrow horizontal grille treatment, faired headlamps, flowing front fenders, and a divided windshield. Behind the cab, the upper body continued without the abrupt visual break typical of a commercial chassis. Rear-wheel valances or skirts completed the effect, although access panels and trim details could differ with the body order and subsequent repair history.

The family resemblance to Chrysler Corporation’s Airflow passenger cars was intentional at the level of appearance, but the relationship should not be overstated. The truck did not adopt the passenger car’s architecture wholesale. It remained a body-on-frame commercial vehicle intended to carry a substantial load over urban and regional routes.

Market Conditions

During the Depression, fleet purchases had to justify themselves. A streamlined specialty body cost more than standard commercial coachwork, so the clearest business case came from companies that valued publicity as well as transport. Fuel distributors were particularly well suited to the form because a tank could be enclosed within a clean, tapered shell without sacrificing the vehicle’s basic function.

No homologation requirement or organized motorsport program drove the LM-70 or LM-71. Their competition took place on delivery routes and in corporate advertising, not on a racing circuit. Comparisons with streamlined promotional vehicles such as the Texaco “Doodlebug” are understandable, but the famous Doodlebug was a separate design on a different chassis and should not be identified as a Dodge LM-series Airflow.

Engine and Drivetrain

The best-documented late LM-series examples use Dodge’s 241.5-cubic-inch inline six. This was a water-cooled L-head, or flathead, engine, with the valves located in the cylinder block rather than in an overhead cylinder head. Its priorities were low-speed pulling ability, compact height, modest manufacturing cost, and straightforward fleet maintenance.

A single carburetor supplied the engine, with mixture and specification dependent on year and equipment. Conventional battery-and-coil ignition fired six spark plugs, while a mechanically driven water pump circulated coolant through the block, head, and radiator. Pressure lubrication served the principal engine bearings, but restorers should consult the correct Dodge truck service literature before assuming that every oiling detail matches a contemporary passenger-car six.

Power passed through a dry single-plate clutch to a four-speed manual gearbox and then by propeller shaft to the rear axle. The low ratios suited a laden truck, and the transmission was never intended to provide passenger-car synchromesh refinement. Published output figures can differ by model year and rating convention, so the 87 bhp figure below applies to a documented 1938 specification rather than every LM-70 or LM-71 built.

The flathead six is not exotic in isolation, which is useful for an owner. The complication lies in confirming that a particular block, cylinder head, intake, carburetor, distributor, and accessory arrangement belong to the truck’s year and duty rating. A later Chrysler-family flathead may fit and run well while remaining incorrect for a high-level restoration.

Chassis, Suspension, Steering, and Brakes

The streamlined shell was mounted on a separate commercial frame. A rigid beam front axle and live rear axle were suspended by semi-elliptic leaf springs, a layout chosen for payload capacity and resistance to rough road surfaces. Lever-operated steering acted through a conventional linkage, and the substantial steering wheel provided the leverage needed at parking speeds.

Dodge had adopted four-wheel hydraulic braking in its truck range, giving the Airflow a more progressive system than the mechanical brakes still found on some earlier commercial vehicles. The system nevertheless relies on large drums, wheel cylinders, steel lines, hoses, and correct adjustment. Heat capacity and pedal effort remain those of a prewar truck, particularly when the vehicle carries a load.

Wheel and tire specifications can differ according to chassis rating and body order. Surviving trucks frequently use dual rear wheels concealed behind removable aerodynamic panels. Restorers should establish the original rim type, diameter, offset, lock-ring design, and tire profile from documentation and physical evidence rather than copying a restored example.

The principal chassis features are conventional, but the body’s integration makes routine access unusually important. Panels that should detach for wheel, brake, or drivetrain service are sometimes welded or permanently filled during cosmetic restorations, creating maintenance problems that the original body builder did not intend.

None of this running gear was designed to make the truck corner like an Airflow sedan. Its frame, spring rates, steering ratio, and axle capacity reflect commercial service. The visual promise of speed belongs mainly to the body, while the chassis delivers the deliberate responses expected of a loaded 1930s tanker.

Driving Experience and Road Manners

From the driver’s seat, the first impression is scale and restricted visibility rather than aerodynamic sophistication. The split windshield and broad body corners require judgment, while the steering is heavy when stationary. Once moving, the large wheel and slow ratio produce steady directional control, though little of the self-centering precision expected from a modern steering box.

The long-stroke flathead six should pull cleanly from low engine speed when its carburetor, ignition, and compression are healthy. Throttle response is measured, and progress depends on using the four-speed gearbox intelligently rather than holding each ratio to high rpm. An unrestored or incorrectly adjusted linkage can make the shift feel obstructive, but even a properly sorted truck asks for deliberate clutch and lever movements.

Leaf springs and heavy axles create a firm, busy ride when the vehicle is empty. Added load settles the chassis, although body roll, brake distance, and tire loading increase. The hydraulic drums can provide predictable retardation when round, dry, and correctly adjusted, but repeated hard stops expose their limited heat capacity.

The body can also act as an acoustic chamber. Engine, fan, gear, axle, and panel noise occupy the cab, particularly if insulation and mounting pads have been omitted during restoration. This is an industrial vehicle with an extraordinary silhouette, not a luxury car hidden beneath commercial sheet metal.

Identification and Originality

Serial Numbers, Engine Numbers, and Model Codes

An LM-70 or LM-71 should be identified from its original Dodge serial or chassis plate, frame evidence, engine number, body-builder tags, and surviving paperwork. The term VIN is commonly applied for convenience, but these trucks predate the standardized 17-character Vehicle Identification Number. A short factory serial number should not be decoded using modern VIN conventions.

LM-70 and LM-71 are factory model or chassis designations, not styling nicknames. Published secondary sources do not always agree on every rating or body-order distinction between the two, and surviving specialty bodies were not necessarily identical. A seller’s assertion that a chassis is an LM-series Airflow is therefore not enough. The serial plate, frame, drivetrain type, dimensions, body construction, and ownership record must support one another.

Engine numbers matter, but “matching numbers” requires period-appropriate interpretation. Dodge did not use the later collector-car practice of stamping a complete vehicle VIN on every major component. An engine with the correct type and date range may be period-correct without being provably original to the chassis, while factory records or old fleet documents may establish a stronger connection.

Body Authenticity

The body is the decisive part of any authentication. Original construction methods, panel seams, internal framing, access doors, tank supports, hinge types, fasteners, and old paint layers deserve careful study before abrasive stripping or disassembly. Newly fabricated bodywork can reproduce the broad silhouette while missing the original compound curves, panel breaks, wheel openings, grille details, and service access.

Surviving tankers also demand an inspection of the vessel itself. The visible streamlined shell and the liquid tank may be distinct structures, and a replacement tank can alter mounts, weight distribution, plumbing, and panel fit. Any plan to carry fuel or another liquid requires professional certification and compliance work beyond a normal historic-vehicle inspection.

Paint, Trim, and Fleet Liveries

Bright petroleum-company liveries contribute heavily to the model’s appeal, but a famous logo is not proof of period service. Restorers should look for photographs, fleet numbers, delivery records, paint strata in protected areas, signwriter’s outlines, and body-order documentation. A truck restored in Texaco colors may be visually convincing without having been a Texaco vehicle when new.

There is no single universal LM-70 or LM-71 paint code because commercial bodies could be finished to customer requirements. The same caution applies to upholstery, instrument panels, mirrors, marker lamps, hose equipment, and rear hardware. Period photographs of the individual truck or the original fleet offer stronger evidence than another restored Airflow.

Variant and Model-Code Breakdown

The surviving record supports treating LM-70 and LM-71 as closely related factory chassis or order codes within the streamlined Dodge commercial family. Body configuration and customer equipment can be at least as significant as the code itself, and exact production totals for each are not consistently published.

These were not trim levels in the passenger-car sense. A body builder and fleet customer could determine tank hardware, storage compartments, lighting, paint, signs, mirrors, and interior fittings. Two genuine trucks can therefore differ in visible detail without either being incorrect.

Performance and Dimensional Specifications

Airflow trucks were not subjected to the standardized magazine acceleration testing later applied to performance cars. Reliable period 0–60 mph, quarter-mile, and maximum-speed figures are not consistently available for the LM-70 and LM-71, and payload would have changed any result substantially. The figures below are limited to a documented late specification commonly associated with a restored 1938 truck.

Claims of high cruising speed should be treated cautiously. Engine rpm, cooling capacity, brake reserve, tire construction, steering wear, and final-drive ratio define a safe road speed more accurately than the body’s appearance. Before touring, an owner should calculate engine speed from the measured tire circumference, gearbox ratio, and confirmed rear-axle ratio.

Compared With Related Dodge and Streamlined Trucks

Versus a Conventional Dodge Heavy Truck

A conventional Dodge truck of the same period can share the basic engine family, gearbox type, axles, brakes, and frame engineering. Its separate cab, exposed fenders, open running boards, and simple freight or tank body are easier to repair and provide better access. The Airflow’s collector premium comes from specialized coachwork and documented history, not from a fundamentally more advanced powertrain.

Versus Chrysler and DeSoto Airflow Passenger Cars

Chrysler and DeSoto Airflow automobiles used streamlined styling around passenger-car requirements, with seating, ride, and structural design developed for an automobile rather than a loaded commercial chassis. The Dodge truck borrows the visual language of rounded leading surfaces, integrated forms, and horizontal detailing, but uses a separate frame, heavy axles, leaf springs, and truck gearing.

Versus the Texaco Doodlebug

The Texaco Doodlebug is frequently confused with any red streamlined tanker. It was a distinct 1930s industrial design associated with Norman Bel Geddes and a different chassis, not an LM-70 or LM-71. Correct identification begins with the underlying manufacturer and serial data, not the color, oil-company lettering, or general teardrop form.

Versus Later Cab-Over Trucks

Later cab-over-engine trucks pursued packaging efficiency by placing the driver above or ahead of the powertrain, shortening the vehicle for a given load length. The Dodge Airflow used its body to create a continuous aerodynamic profile, but its layout and service arrangements remained rooted in prewar commercial practice. It should not be assumed to have the tilt-cab access or space efficiency of a postwar COE.

Ownership and Restoration Notes

Mechanical Parts and Rebuilding

Dodge flathead-six expertise remains available because related engines served in numerous cars, trucks, and industrial applications. Bearings, pistons, valves, ignition parts, gaskets, and cooling-system components can often be sourced or adapted by specialists. The challenge is choosing components that match the truck engine’s displacement, duty specification, and external appearance.

Before rebuilding, inspect the block for freeze cracks, corrosion around water passages, worn valve seats, cylinder taper, and previous overboring. Cooling problems often originate in scale-filled water jackets, a restricted radiator core, a worn water pump, or missing sheet-metal air-management pieces rather than in the basic engine design.

Gearbox and axle repairs require identification before parts ordering. Worn bearings, chipped gear teeth, damaged synchronizing equipment where fitted, leaking seals, and excessive differential backlash can turn a running display vehicle into a costly mechanical project. Clutch linkage and engine mounts also deserve attention because body access is restricted.

Body Structure and Corrosion

The streamlined body is the financial center of any restoration. Inspect lower skirts, wheel openings, door bottoms, cab corners, floor edges, compartment doors, tank supports, and seams where moisture can sit between overlapping panels. Old filler can conceal stretched metal, welded access panels, or fabricated curves that depart significantly from the original profile.

Internal framing may corrode while the exterior remains presentable. Where dissimilar metals, wood packing, or rubber isolators were used, trapped moisture can damage both the skin and its support. Photographing and measuring the body before dismantling is essential because an incomplete shell may offer few reliable reference points during reassembly.

Brakes, Wheels, and Tires

A complete hydraulic overhaul is prudent on a truck with unknown service history. Wheel cylinders, master cylinder, hoses, hard lines, return springs, drums, and linings must be assessed as a system. Fluid contamination or a cosmetically restored master cylinder can undermine otherwise sound brakes.

Multi-piece commercial rims require inspection by a shop experienced with vintage truck wheels. Corrosion, distorted lock-ring grooves, mismatched components, or incorrect assembly can be dangerous. Modern replacement wheels may improve serviceability but can alter track, clearance, hubcap fit, and the stance within the close-fitting skirts.

Restoration Difficulty

Mechanical work is generally more manageable than body reconstruction. Grilles, lamps, trim strips, handles, access covers, glass patterns, badges, and fleet-specific hardware may have to be repaired or recreated individually. Reproduction support is limited compared with mainstream Dodge passenger cars and light pickups.

Documentation should guide the project before paint or fabrication begins. Period photographs, old registrations, body tags, fleet records, correspondence, and unrestored details can save hundreds of hours of guesswork. A restoration that preserves original body fabric and establishes the truck’s identity usually carries greater historical weight than a flawless but undocumented reconstruction.

Buyer and Inspection Points

An Airflow truck purchase requires two inspections: one for the Dodge chassis and another for the specialty body. The latter usually presents the greater financial risk, particularly when a familiar livery distracts from missing serial evidence or newly fabricated coachwork.

A complete but tired truck can be a better acquisition than a freshly painted example assembled from undocumented parts. Original templates, brackets, trim, and damaged panels retain information that disappears once they are discarded. For this model, completeness and evidence often matter more than immediate drivability.

Collector and Market Relevance

Collector demand centers on genuine specialty-bodied trucks with traceable histories, intact serial evidence, and a high proportion of original Gar Wood-era fabric. Tankers attract particular attention because the continuous body shape expresses the Airflow concept most clearly. Correct petroleum-company provenance adds another layer, but only when records support the graphics.

Public auction appearances are infrequent, and individual trucks differ too much in authenticity, body completeness, restoration quality, and provenance for a simple price guide to be useful. A documented original, a reconstructed truck on a genuine LM chassis, and a later replica can look similar in photographs while representing very different historical objects.

Collectors also value operational practicality. A truck that starts, cools, steers, shifts, and stops properly can participate in concours displays, commercial-vehicle gatherings, and marque events without relying on static presentation. Even so, transport dimensions, enclosed storage, tire capacity, and loading equipment make ownership substantially more involved than keeping a prewar Dodge automobile.

Cultural Relevance

The Dodge Airflow truck belongs to the 1930s movement that applied streamlining to locomotives, buses, aircraft, appliances, and industrial design. Its curved surfaces communicated speed and technical progress whether or not the vehicle travelled quickly. On a fuel-delivery route, the body converted an ordinary commercial task into a daily public exhibition.

Its modern cultural life is concentrated in concours competition, commercial-vehicle collections, petroleum memorabilia circles, and restorations commissioned as centerpieces for corporate or private museums. The combination of a recognizable oil-company livery and the enclosed, almost architectural body form gives it an appeal beyond Dodge specialists.

That popularity creates an identification hazard. Replicas and imaginative restorations may be displayed under the broad Dodge Airflow name without a documented LM-70 or LM-71 chassis. They can be impressive pieces of fabrication, but they should be described accurately rather than folded into the surviving factory population.

Frequently Asked Questions

What engine did the Dodge LM-70 Airflow Truck use?

Documented late examples use a Dodge 241.5-cubic-inch, or 3,958 cc, L-head inline six-cylinder gasoline engine. A 1938 specification lists 87 bhp. Engine type and output should be confirmed against the year and serial evidence because published figures are not uniform across every LM-series truck.

What is the difference between an LM-70 and an LM-71?

LM-70 and LM-71 are related Dodge factory chassis or order designations, not separate styling packages. Surviving published material does not support treating every visual feature or body type as exclusive to one code. The original serial plate, chassis dimensions, body documentation, and factory records should establish the specific identity.

Were Dodge Airflow trucks built by Gar Wood?

Dodge supplied the underlying commercial chassis and powertrain, while Gar Wood Industries is closely associated with the specialized streamlined coachwork found on surviving examples. The truck should therefore be evaluated both as a Dodge chassis and as a coachbuilt commercial body.

Is the Dodge Airflow tanker the same vehicle as the Texaco Doodlebug?

No. The famous Texaco Doodlebug was a separate streamlined tanker design on a different chassis. A Dodge LM-70 or LM-71 restored in Texaco colors should not be called a Doodlebug, and the livery alone does not prove original Texaco service.

How can an authentic LM-70 or LM-71 be identified?

Begin with the original Dodge serial or model plate, frame evidence, engine number, body-builder tags, and historical paperwork. Then compare body seams, internal framing, mounting points, access panels, and period photographs. A modern 17-character VIN decoder does not apply to these prewar serial numbers.

Are parts available for a Dodge Airflow Truck restoration?

Some flathead-six service parts, ignition components, brake pieces, bearings, and engine internals can be sourced through vintage Dodge and industrial-engine specialists. Airflow-specific body panels, grille parts, trim, skirts, doors, and tanker hardware are scarce and usually require restoration or one-off fabrication.

What makes an LM-series Airflow Truck expensive to restore?

The compound-curved body, hidden support structure, missing trim, commercial brake and wheel equipment, and lack of model-specific reproduction parts dominate the budget. Authenticating the chassis and livery can also require extensive research. A largely complete truck with poor paint may be less costly to restore accurately than a polished example missing original body structure.

Collector Takeaway

The LM-70 and LM-71 are compelling because their extraordinary appearance rests on ordinary, serviceable Dodge truck engineering. The flathead six, four-speed gearbox, beam axles, leaf springs, and hydraulic drums explain how the vehicle worked. Gar Wood’s closely integrated shell explains why a fleet operator could use it as both a tanker and a public statement about modernity.

The body is also the reason every surviving example demands skepticism. Serial evidence, original construction, period photographs, and fleet history matter more than a famous red paint scheme or a mirror-finished restoration. A properly documented Dodge Airflow truck preserves a rare form of 1930s industrial coachbuilding, one in which commercial utility and corporate theatre were formed from the same sheet metal.