Dana Spicer AdvanTEK 40 Tandem Axle

Quick Facts

Manufacturer: Dana Incorporated
Brand: Spicer
Product Family: AdvanTEK
Axle Type: Tandem drive axle
Drive Configuration: 6×4
Nominal Tandem Capacity: 40,000 lb
Primary Applications: Class 8 linehaul, regional-haul, and selected vocational trucks
Forward-Axle Models: D40-155 and D40-156
Gear Design: Single-reduction hypoid gearing optimized for drivetrain efficiency
Fastest Common Ratio: 2.26:1
Differential Options: Standard wheel differentials and optional driver-controlled differential locks
Notable Options: Lube pump, SelecTTrac configuration, 11 mm wall housing, and Spicer LMS or LMSi wheel ends
Primary Design Goal: Support engine downspeeding while reducing weight, friction, and operating costs

Overview

The Dana Spicer AdvanTEK 40 is a 40,000-pound tandem commercial truck drive axle developed primarily for Class 8 linehaul and regional-haul trucks. It combines fast axle ratios, high-torque capability, reduced lubricant volume, and optimized inter-axle driveline geometry.

The axle is particularly associated with engine-downspeeding powertrains. These drivetrains use a direct-drive or carefully selected overdrive transmission, a fast axle ratio, and an engine capable of producing strong torque at lower operating speeds.

Dana offers the AdvanTEK 40 in D40-155 and D40-156 configurations for linehaul and vocational applications. Exact ratings, housings, wheel ends, brakes, differential locks, and ratio availability depend on the truck manufacturer’s approved specifications.

Key Characteristics

The AdvanTEK 40 uses Dana’s AdvanTEK gearing to transmit higher input torque through numerically lower axle ratios. This allows a properly matched engine to operate at reduced rpm during highway cruising.

Its design incorporates lower lubricant requirements and reduced internal churning losses. Dana identifies a lubricant-volume reduction of approximately six pints compared with its standard axle design, although the correct fill quantity must always be confirmed for the particular model and installation.

The tandem’s inter-axle driveline geometry is designed to create favorable operating angles with many air-ride suspensions. Proper driveline alignment can help reduce noise, vibration, universal-joint loading, and premature driveline wear.

Depending on configuration, the assembly may be lighter than a comparable conventional tandem axle. Dana states that current configurations can be up to approximately 37 pounds lighter than its referenced standard axle.

How the Axle or Differential Works

The AdvanTEK 40 consists of a forward drive axle and a rear-rear drive axle connected by an inter-axle driveshaft. Engine torque travels through the transmission and main driveshaft to the forward axle’s input shaft.

A power divider inside the forward carrier divides torque between the two drive axles. Part of the torque turns the forward axle’s ring gear and wheel differential, while the remaining torque passes through the output shaft and inter-axle driveshaft to the rear axle.

Each wheel differential permits the left and right wheels on its axle to rotate at different speeds while the truck turns. If equipped with driver-controlled differential locks, the operator can temporarily restrict this differential action to improve traction on slippery or uneven surfaces.

The ring-and-pinion gears provide the axle’s final reduction. A 2.26:1 ratio means the driveshaft turns approximately 2.26 times for one rotation of the drive wheels.

For a broader explanation of these components, see How Commercial Truck Axles and Differentials Work.

Axle Position and Function

The forward member of the tandem mounts ahead of the rear-rear axle. It contains the power divider, forward wheel differential, and output mechanism that transfers power to the second axle.

The rear-rear axle receives torque from the short inter-axle driveshaft and distributes it to its left and right wheels.

Together, the two axles support the rear of a 6×4 tractor or truck while providing four driven wheel positions. The suspension equalizes load across the tandem, but correct weight distribution still depends on wheelbase, fifth-wheel placement, cargo position, and applicable weight limits.

Common Specifications

Axle Configuration: Tandem drive axle for 6×4 vehicles
Nominal Tandem Rating: 40,000 lb
Product Models: D40-155 and D40-156
Primary Vehicle Class: Class 8
Reduction Type: Single reduction
Common Fast Ratios: 2.26, 2.39, 2.47, 2.53, 2.64, and 2.79
Broader Ratio Availability: Selected configurations may extend through conventional ratios as high as approximately 3.91
Housing Options: Standard and heavy-wall configurations, including an available 11 mm wall housing
Traction Equipment: Inter-axle differential lock with optional wheel differential locks
Lubrication Options: Standard lubrication or an available axle-driven lube pump
Wheel-End Options: OEM-dependent hub and bearing packages, including Spicer LMS and LMSi systems
Brake Compatibility: Drum or air-disc brake packages according to the truck manufacturer’s axle installation
Suspension Compatibility: Approved tandem suspensions with application-specific brackets, track widths, and driveline geometry

Actual ratings and available equipment must be verified through the vehicle manufacturer, Dana application guidelines, and the axle identification records.

Axle Ratios and Gearing

The AdvanTEK 40 became well known for ratios intended to support engine downspeeding. Common fast ratios have included 2.26, 2.39, 2.47, 2.53, 2.64, and 2.79.

The 2.26 through 2.79 range is especially relevant to direct-drive transmission specifications. Other AdvanTEK 40 configurations have been offered with numerically higher ratios extending toward 3.91 for use with overdrive transmissions or applications needing different startability and grade-performance characteristics.

A fast ratio reduces engine rpm at a given road speed, but it also reduces torque multiplication at the wheels. Transmission gearing, tire size, gross combination weight, terrain, cruise speed, engine torque curve, and startability requirements must therefore be evaluated as a complete system.

The lowest numerical ratio is not automatically the most efficient choice. A ratio that forces frequent downshifts or keeps the engine below its efficient operating range may produce worse results than a slightly slower ratio.

See Commercial Truck Axle Ratios Explained for additional ratio-selection guidance.

Differential and Traction Options

The tandem includes a lockable inter-axle differential, commonly called the power-divider lock. Engaging it helps prevent one axle from receiving most of the available torque when traction differs between the forward and rear-rear axles.

Driver-controlled wheel differential locks may also be available. These locks improve traction by restricting speed differences between the left and right wheels on an axle.

Some vehicle specifications offer wheel locks on one axle, while others may provide locks on both drive axles. Availability depends on the axle model, truck manufacturer, and chosen build configuration.

Differential locks are intended for low-traction conditions. They should be operated according to the truck and axle manufacturer’s instructions because improper engagement, tight turns on dry pavement, or excessive wheel-speed differences can damage tires and drivetrain components.

Learn more in Open vs Locking vs Limited-Slip Differentials.

Brake and Wheel-End Options

AdvanTEK 40 installations may use S-cam drum brakes or commercial air-disc brakes. Brake type, rotor or drum dimensions, chamber size, slack-adjuster arrangement, and antilock-braking components are determined by the vehicle specification.

Available wheel-end configurations may include conventional serviceable bearings or Spicer LMS and LMSi low-maintenance systems. Hub material and single- or dual-tire arrangements also vary by installation.

Dana’s SelecTTrac option is intended to support wheel-bearing life and axle-rating requirements in selected configurations, including applications using aluminum hubs or wide-base single tires.

Brake and wheel-end replacement parts must be matched by axle model, axle serial number, hub configuration, brake family, and OEM build information rather than by the AdvanTEK 40 name alone.

Common Applications

Long-distance highway tractors
Regional-haul tractors
Pickup-and-delivery tractors
Dry-van operations
Refrigerated freight operations
General freight fleets
Fuel-conscious Class 8 fleet applications
Trucks using direct-drive automated manual transmissions
Powertrains designed for reduced cruise rpm
Selected vocational applications approved for the axle rating and duty cycle

Truck, Suspension, and Drivetrain Compatibility

The AdvanTEK 40 is used in Class 8 trucks equipped with a 6×4 tandem-drive layout. Compatibility depends on the chassis manufacturer’s axle offering, suspension geometry, engine rating, transmission, driveshaft series, tire revolutions per mile, and expected operating weight.

Fast-ratio versions are commonly paired with direct-drive automated manual transmissions and engines calibrated for high torque at low rpm. Certain ratios and torque ratings may require a specific Spicer driveshaft series, such as the SPL 350.

The axle has been offered with various air-ride suspensions. Its inter-axle driveline arrangement is designed to support favorable universal-joint angles, but installation measurements and suspension travel still must remain within Dana and OEM limits.

A truck should not be converted to an extremely fast ratio based only on desired cruise rpm. Startability, clutch or transmission loading, driveline torque, gradeability, application severity, and warranty coverage must also be evaluated.

Advantages

Fast axle ratios support lower engine speed during highway cruising
AdvanTEK gearing is designed to handle the higher input torque associated with downsped engines
Reduced internal friction and lubricant churning can improve drivetrain efficiency
Lower lubricant volume reduces carried fluid weight
The assembly may be lighter than a comparable standard 40,000-pound tandem
Optimized inter-axle driveline angles can reduce noise and vibration
Favorable driveline geometry may extend universal-joint life
Optional lube pump helps maintain gear lubrication in demanding operating conditions
Available inter-axle and wheel differential locks improve traction
Multiple housing and wheel-end choices allow the axle to be tailored to fleet requirements
Broad parts and service support is available through Dana and Spicer distributors

Limitations or Considerations

Fast ratios must be matched carefully to engine torque, transmission gearing, tire size, vehicle weight, and terrain
An excessively fast ratio can reduce startability and grade performance
Downsped operation may increase torque loading on driveshafts, universal joints, and axle components
Certain ratios may require a specific high-capacity driveshaft
A 40,000-pound nominal tandem rating does not override legal axle-weight limits
Vocational or severe-service operation may require a heavier axle, housing, suspension, or different ratio
Differential-lock availability varies by model and OEM specification
Actual lubricant capacity depends on the axle model, installation angle, and optional equipment
Technicians need correct Dana procedures and tools for carrier and differential setup
Early and current AdvanTEK 40 configurations may not use identical parts
The newer AdvanTEK 40 Pro should not be assumed to have the same specifications as the original AdvanTEK 40

Driver and Operator Experience

In a properly matched highway powertrain, drivers may notice lower engine rpm at cruising speed. The cab can feel quieter, and the engine may spend more time within a narrow, fuel-efficient operating range.

Fast gearing also changes how the truck responds under load. The transmission may downshift earlier on grades because the axle provides less torque multiplication than a numerically higher ratio.

Drivers should avoid full-power acceleration when one wheel is spinning. Sudden traction recovery can create damaging shock loads through the wheel differential, power divider, axle shafts, and driveline.

The inter-axle and wheel differential locks should be engaged only under the conditions described in the vehicle operator’s manual. Indicator lights should be monitored to confirm when each lock engages and releases.

Maintenance and Ownership Notes

Lubricant type, fill level, drain interval, and inspection procedures should follow Dana service literature and the vehicle manufacturer’s maintenance schedule. The lubricant must meet the specification required for the axle and its operating conditions.

Routine inspections should check the pinion seal, input and output seals, differential covers, wheel seals, breather, lube-pump system when equipped, and housing for leaks or damage.

Technicians should also examine inter-axle driveshaft universal joints, yokes, fasteners, ride height, and driveline angles. A suspension ride-height problem can change joint operating angles and create vibration even when the axle itself is functioning properly.

Axle-ratio changes require compatible gearing in both tandem carriers. Installing mismatched ratios in the forward and rear-rear axles can cause severe driveline binding and component failure.

Accurate model and serial numbers should be recorded before ordering carriers, gear sets, seals, bearings, differential locks, or wheel-end parts.

Common Axle or Differential Problems

Common problems can include lubricant leaks at the pinion, output, wheel, or differential-cover seals. A clogged breather or excessive lubricant level may contribute to leakage.

Gear whine can result from worn bearings, incorrect pinion depth, improper backlash, damaged gear teeth, or a poorly set replacement gear set. A noise that changes between acceleration and coast conditions can help technicians narrow the source.

Power-divider problems may produce inter-axle differential noise, loss of drive to one axle, failure to lock, or failure to disengage. Pneumatic controls, wiring, switches, shift components, and internal gearing should all be inspected.

Wheel differential locks may fail to engage because of low air pressure, an electrical or pneumatic control problem, damaged shift components, or internal differential wear.

Other concerns include overheating, contaminated lubricant, loose yokes, universal-joint wear, wheel-bearing issues, and vibration caused by incorrect suspension ride height or driveline angles.

See Common Truck Axle and Differential Problems for a broader diagnostic overview.

Identification Information

Primary Model Families: D40-155 and D40-156
Axle Type: Tandem drive axle
Nominal Capacity: 40,000 lb
Identification Source: Axle tag, carrier tag, housing stampings, and OEM build records
Important Numbers to Record: Model number, serial number, specification or bill-of-material number, ratio, and carrier identification

The primary axle-identification tag is normally attached to the axle housing or carrier area. Its location can vary between the forward and rear-rear axle assemblies.

D40-155 and D40-156 identify AdvanTEK 40 product configurations, but suffixes and OEM codes provide additional information about the housing, differential locks, brakes, wheel ends, and other equipment.

The forward and rear-rear axles have different carriers and functions. Parts should not be selected merely because both housings belong to the same tandem.

If the tag is missing or unreadable, check the truck’s build sheet, axle housing stampings, carrier markings, ring-gear information, and OEM service records. Photographs and physical measurements may also be necessary.

Use How to Identify a Truck Axle or Differential before purchasing replacement parts.

Buying Considerations

Confirm the complete forward and rear-rear axle model numbers
Verify the axle serial numbers and original build specifications
Determine whether the purchase is a complete tandem, carrier assembly, housing, or individual component
Confirm the ratio and ensure both drive axles use matching gearing
Check the nominal axle rating and housing wall thickness
Identify all inter-axle and wheel differential locks
Determine whether the axle has a lubrication pump
Verify drum-brake or air-disc-brake compatibility
Confirm hub, bearing, spindle, and wheel-end specifications
Check track width and suspension-bracket placement
Verify driveshaft and yoke compatibility
Inspect used gears for scoring, pitting, overheating, and abnormal wear patterns
Inspect housings for cracks, corrosion, bent tubes, and damaged mounting surfaces
Check pinion, input, and output areas for leakage or looseness
Ask for maintenance records and lubricant history when buying a used assembly
Confirm whether the unit is the original AdvanTEK 40 or the newer AdvanTEK 40 Pro
Compare the seller’s part numbers with current Dana and OEM records
Include freight, core charges, setup labor, lubricant, seals, and installation parts in the total cost

Variants and Configurations

D40-155 forward-axle configuration
D40-156 forward-axle configuration
Standard housing configuration
Available 11 mm heavy-wall housing
Standard wheel differentials
Driver-controlled wheel differential-lock configurations
Power-divider lock
Standard lubrication arrangement
Optional axle-driven lubrication pump
Spicer LMS wheel ends
Spicer LMSi wheel ends
Dual-tire configurations
Wide-base single-tire configurations
Drum-brake installations
Air-disc-brake installations
Linehaul specifications
Approved vocational specifications
Fast-ratio downspeeding configurations
Conventional overdrive-transmission configurations
SelecTTrac-equipped configurations

Comparison to Similar Equipment

Compared with a conventional 40,000-pound tandem using a numerically higher axle ratio, the AdvanTEK 40 places greater emphasis on reduced engine rpm, lower friction, and powertrain downspeeding.

The Meritor 14X Tandem Drive Axle serves many similar Class 8 applications. The best choice depends on OEM availability, ratio coverage, driveline integration, fleet parts inventory, service familiarity, differential options, and total vehicle specification.

Compared with heavier vocational tandems, the AdvanTEK 40 is generally better suited to highway-oriented operations where a 40,000-pound tandem rating is sufficient. Severe off-road, heavy-haul, logging, mining, and other high-shock-load applications may require a heavier axle family.

The Dana Spicer AdvanTEK 40 Pro is a newer evolution of the platform. It expands ratio coverage and raises certain powertrain capabilities, but its specifications and components should be evaluated separately from those of the original AdvanTEK 40.

Best Fit For

Class 8 highway tractors
Linehaul fleets focused on fuel efficiency
Regional-haul operations with substantial highway mileage
Fleets using engine-downspeeding powertrains
Trucks equipped with direct-drive automated manual transmissions
Applications needing fast axle ratios such as 2.26 through 2.79
Operations that can benefit from reduced axle and lubricant weight
Fleets seeking a 40,000-pound tandem with optional differential locks
Trucks operating primarily on paved roads
Operators with access to Dana Spicer parts and service support

Related Truck Types

Sleeper Trucks
Day Cab Trucks
Regional-Haul Trucks
Linehaul Trucks
Class 8 Trucks
Semi Trucks

Related Truck Models

Related Axle and Differential Types

Related Equipment Systems

Related Guides

Regulatory and Compliance Notes

The AdvanTEK 40’s nominal 40,000-pound tandem rating is a manufacturer equipment rating, not automatic permission to carry that weight on every road.

Allowable weight depends on federal, state, provincial, and local regulations; tire and wheel ratings; suspension capacity; gross axle weight ratings; axle spacing; bridge-formula requirements; and the vehicle’s certified gross weight ratings.

Brake equipment must comply with the requirements applicable to the completed vehicle. ABS wheel-speed sensors, tone rings, brake chambers, slack adjusters, rotors, drums, and friction components must remain compatible with the original safety system.

Changes to axle ratio, tires, brakes, suspension ride height, or driveline components can affect speedometer calibration, electronic powertrain programming, braking performance, stability systems, emissions operation, and warranty coverage.

Real World Operating Notes

The AdvanTEK 40 delivers its greatest potential benefit when the entire powertrain is engineered for downspeeding. Installing a fast ratio without matching the engine, transmission, driveshaft, tires, vehicle weight, and route may not improve fuel economy.

Linehaul trucks operating at steady highway speeds are more likely to benefit from very fast ratios than trucks that regularly start on grades, operate off road, or spend most of their time in stop-and-go service.

Drivers and maintenance departments should watch for driveline vibration after suspension work, ride-height changes, or universal-joint replacement. The axle’s optimized geometry still depends on the truck remaining at its specified ride height.

Used AdvanTEK 40 tandems can be attractive replacement assemblies, but model, ratio, housing, lock, brake, wheel-end, yoke, and suspension details must match the receiving truck.

Frequently Asked Questions

What is the Dana Spicer AdvanTEK 40?

The Dana Spicer AdvanTEK 40 is a 40,000-pound tandem drive axle designed for Class 8 6×4 trucks. It emphasizes efficient gearing, lower weight, reduced lubricant volume, and compatibility with engine-downspeeding powertrains.

What are the D40-155 and D40-156?

D40-155 and D40-156 are product models within Dana’s AdvanTEK 40 family. Exact configuration details and suffixes should be verified through the axle tag, Dana documentation, and the truck manufacturer’s build records.

What is the fastest AdvanTEK 40 ratio?

The original AdvanTEK 40 is commonly associated with a 2.26:1 ratio. The newer AdvanTEK 40 Pro offers additional ratio choices and should be treated as a separate product configuration.

What ratios are commonly available?

Common downspeeding ratios include 2.26, 2.39, 2.47, 2.53, 2.64, and 2.79. Other configurations may use numerically higher ratios. Availability varies by model year, truck manufacturer, transmission, and application.

Is the AdvanTEK 40 intended only for direct-drive transmissions?

No. Fast ratios are strongly associated with direct-drive transmissions, but numerically higher axle ratios have also been offered for overdrive-transmission powertrains.

Does the AdvanTEK 40 have locking differentials?

The tandem includes a power-divider lock, and driver-controlled wheel differential locks may be available. The number and location of wheel locks depend on the ordered configuration.

What does the optional lube pump do?

The axle-driven pump helps keep critical gearing lubricated and provides additional protection during demanding operating conditions, including situations that can otherwise reduce lubricant delivery.

Can an AdvanTEK 40 replace another 40,000-pound tandem?

Possibly, but equal capacity does not guarantee compatibility. Ratio, suspension mounts, track width, driveline length, yokes, brakes, wheel ends, electronics, ride height, and OEM approvals must all be checked.

Can the axle ratio be changed?

Yes, but both tandem carriers must use matching ratios. The new ratio must also be compatible with the transmission, engine, driveshaft, tires, electronic programming, vehicle weight, and duty cycle.

Is the AdvanTEK 40 suitable for heavy haul?

It may be used in approved applications within its ratings, but specialized heavy-haul and severe vocational work often requires a higher-capacity axle family. Application approval should be obtained before specifying it for unusually high loads or severe duty.

Is the AdvanTEK 40 the same as the AdvanTEK 40 Pro?

No. The AdvanTEK 40 Pro is a newer development with expanded ratio coverage and other design updates. Parts and published capabilities should not be assumed to interchange with the original AdvanTEK 40.

How can I identify the correct replacement parts?

Use the complete model number, serial number, specification information, ratio, carrier tag, OEM build records, and wheel-end and brake details. The product-family name alone is not sufficient.

Availability and Where to Find

The Dana Spicer AdvanTEK 40 may be available as original equipment on selected Class 8 trucks and through Dana-authorized distributors, commercial truck dealers, drivetrain specialists, rebuilders, salvage suppliers, and the aftermarket.

New carrier assemblies, remanufactured carriers, gear sets, bearings, seals, differential components, wheel-end parts, and service literature may be available separately. Complete used tandem assemblies can also be found through heavy-truck recyclers.

Current product details and technical resources are available from Dana’s Spicer AdvanTEK 40 product page and the Spicer aftermarket product page.

Always confirm the model, ratio, capacity, housing, brakes, differential locks, wheel ends, yokes, and suspension configuration before purchasing.

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