Transmission Dyno Stand

Dyno stands allow testing complete gearboxes in assembly checking their performance and understand if it is comparable to benchmark characteristics. It is the tool that is certainly needed to provide certified transmission quality. There are options that allow advanced testing of FWD, RWD, AWD automatic transmission vehicles, for both civil and heavy duty models. A dyno stand used to be an expensive option for big-scale car transmission rebuilders but more accessible quality options start to emerge on the international transmission service market.

Why is it important to use a transmission dyno test stand?

What are key components of a transmission dyno?

What is the difference between electric motor and combustion engine dynos?

Principle of operation | What types of load cells are there in the dynos?

History of transmission dynos on the industry market

Pressure gauges in transmission dynos

Importance of hardware with transmission dyno stands

Importance of software with transmission dyno stands

Major suppliers of automatic transmission dynos

What are you looking for?

The transmission of an essential part of a vehicle drivetrain system, transferring power to the wheels, doing gear switching, distributing load. Depending on the context, to a large degree term ‘transmission’ is synonymous to ‘gearbox’.

What is the utility of using transmission dyno test equipment?

In the transmission repair industry, testing of a complete automatic transmission unit is imperative for large remanufacturing companies dealing with large repair volumes, is quite desirable for medium-scale companies working widely on the national level and supplying to other countries, and is a dream for smaller transmission shops that always do test-on-the-car checks to verify the repair procedure. In addition, many educational institutions (like tech colleges) need dynos for proper students’ skill-learning process. Production companies use transmission dynos in their EOL tests (end-of-line testing).

“Dynamometer” consists of two words - dynamo (Greek for “power in motion”) and meter (also Greek for “measurement”). Very often, it is simply called as “dyno”. A dyno stand used to be a costly tool solely for big-scale transmission rebuild shops, nowadays, however, more accessible options of these tools are emerging on the international transmission service market.

One who is new to transmission repairs may actually wonder: ‘Why a transmission should be dyno tested?’ It is primarily about warranties and guarantees given by the provider of repair services. A dyno test ensures that a transmission is performing well and adequately under certain conditions of operation and this gives a huge grade of certainty that the transmission will last full life expectancy.

The dyno testing means that you mount a transmission in the dyno test rig and drive it through various paces. The idea of such testing is simulation of real-life operation conditions as if it were driven in the car on the road. At this, the gearbox is taken through a complete set of operations, with gear and speed switching, and in each gear operation is performed through the design speed range. Certainly, it is vital to capture output values, and these are monitored in the test process.

Reputable transmission remanufacturers set their goal to return the rebuilt product to original factory specifications. With dyno testing, the following key parameters are checked: torque, temperature, pressure. Also, operations efficiency is checked and sensor functionality test is performed. The tech operator is able to verify bolt torque and presence or absence of leaks in the system. To put it straight, the dyno test assures that your gearbox operates according to the factory specifications with due regard to design speed and range of gears.

You need to dyno test gearboxes when:You strive to provide top quality of your rebuilds.

  1. You want to be sure of the longevity of warranties that you give.
  2. You want to speed up your repair processes.
  3. Your partners who contract you in large volumes need assurance of compliance with highest reman standards.
  4. You value your shop’s reputation and you want to avoid unwanted returns damaging

Basically, without dyno testing you have difficulty proving that the gearbox will not fail in operation conditions. Although the guarantee might have a fault covered, it is your reputation that you need to protect and avoid frustration when a gearbox is returned back with faults.

What is more, health of the transmission means that no harm will be done to the drivetrain and no further damage to the engine. Another vital idea is that a high quality reman transmission can be better performing than a new factory one. This is important for transmission performance shops and racing car workshops.

What are key components of a transmission dyno?

It is important to understand key components of a dyno test rig as a transmission specialist may wonder how it functions.

Primarily, modern dynos are fully digital and allow for highly accurate easy-to-perform repeatable automotive transmission testing. The important factor here is software and hardware, which is realized in the controller system. These dynos simulating automotive load conditions are typically quite universal and adaptable to various modes of wheel drive and automatic transmission types (including CVT transmissions). In order to cover this universality the test rig is performed with due regard to capacity requirements, motor horsepower specs, number of load cells. Let us cover the components of the body of a transmission dyno.

  • High-output motor (nowadays it would be an electric motor)
  • Load unit (for dynamic loaded testing). At this, number of load cells is varied for various applications: 1 unit – for RWD (rear-wheel drive) vehicles, 2 units – for FWD (forward-wheel drive) vehicles, 3 units – for AWD (all-wheel drive) vehicles
  • Jib crane for transmission mounting and dismounting
  • Pumps with hoses to fill and drain transmission fluid
  • Pressure sensors
  • Oil tank and drip trays
  • Stall brake
  • Quick release hose fittings


  • Electric shuttle motors allowing positioning for different transmission configurations
  • Tooling kits for transmission positioning avoiding any potential harm to pumps or certain transmission components
  • Bushings for precise transmission alignment

What is the difference between electric motor and combustion engine dynos?

Modern dynos run on electric motors, they use electricity stored in batteries and power electromagnets driving axles.

Combustion engines run on gasoline, which explodes in an enclosed space – it is a well-known process happening in most of the cars driving on our roads, hence the name. In vehicles, this combustion moves pistons, which rotate engine’s crankshaft and all that controls rotation of the vehicle’s axle. This solution is pretty much obsolete and not used in up-to-date dynos for a number of reasons:

  • CE has many more parts and occupies more space (CE with ~2000 parts and EM with ~20 parts). Fewer parts also means easier serviceability and maintenance.
  • Disposable fuel with electric motors, while in a combustion engine, the disposable fuel is gasoline, which must be carefully stored, as there is a danger of ignition. What is more, fuel leftovers must be exhausted out of the after combustion.
  • Electric motor battery packs are expensive but gradually become more accessible.
  • With electric motors little energy is wasted, but with combustion engines quite a serious percentage of energy is lost along the way. Therefore, it’s the gas-powered vehicle that needs more energy.
  • It is more comfortable and convenient to service an electric motor in a transmission shop surrounding, if comparing to a combustion engine.

Overall, 75kw (or ~100 horse power) is enough to drive modern transmission dynos for light-duty and medium-duty application. At that, electric motors are very much preferred.

Principle of operation

It is important to distinguish transmission test stands from these two types of dyno stands: engine dynamometers and chassis dynamometers. With engine dynos, the engine is removed from the vehicle and installed on the stand by connecting directly to the flywheel. For this purpose, transmission specialists use special adapters and it is also necessary to connect the cooling system, as well as some other components - this procedure takes a lot of time. Engine developers and manufacturers mainly use these stands.

Chassis dynos allow for testing of the vehicle as it is driving on the road, fully assembled. These are rather popular among people doing racing cars or performance vehicles.

Transmission testing stands are suitable for both transmission manufacturers and transmission repair service shops. During testing of complete gearboxes their performance is compared against benchmark characteristics. Multiple readings are taken using corresponding sensors and transducers, their readings are converted to visually explicit and perceivable information. Obviously, transmission dynos vary in their design to cover FWD, RWD, AWD automatic transmission vehicles, support and fit civil light-duty and/or heavy-duty models. Precision alignment tooling and data acquisition & control systems play an important part in quality transmission testing.

What types of load cells are there in the dynos?

Dynamometers are classified by the method of creating a load. Nowadays, the accepted brake standard in a transmission dyno is eddy current brakes.

EC brake is an electrically controlled brake with air cooling. In it, load is created by inducing a magnetic field in a rotating disc. Heat produced by the rotating disc is dissipated in air. Moving parts are stopped by EC brakes with the help of drag force. These brakes are a great option for lower power applications and dynos up to 250 hp.

Water brake works on the transfer of water momentum creating load on the tested unit with the absorbed power heating water. Usually, these consist of a turbine / propeller, which is mounted in an enclosure with water. Water brake are for high power applications far over 250 hp. Largely, for engine dynos with thousands of hp.

Alternating current dynamometers are another option which is less frequent when compared against EC’s. These are used for engine dynos and the idea is in mimicking the load placed on the engine as it powers vehicle.

History of such equipment on the industry market

Transmission testing equipment has a particular history in the USA, the leader of car industry. The world’s largest manufacturer for this type of equipment – PowerTest – is located in Wisconsin. They started in 1976 and grew to acquire a large number of brands and companies from the industry. Nowadays, PowerTest owns such brands as AIDCO, Axiline, Hicklin – all of them shall be known to people who spent decades in the transmission industry.

Another well-known US manufacturer is MAE (Mustang Advanced Engineering) who were on the market since 1970’s as well. As of today, they provide a system for testing automatic passenger car and light truck inline and transverse transmissions as well as systems for medium- and heavy-duty applications.

There are some other companies located in the USA but they are far less active and less known to a global audience, as of today.

Although, dynamometers have been around since as far as the 18 th century, quality transmission dyno options are not as many as one might have thought.

In the 21st century, USA are not sole prominent manufacturers and they need to compete with companies like RayTech from China or Hydra-Test from the UK for the global buying audience.

Pressure gauges in transmission dynos

In previous decades, the equipment output gauges were analog but nowadays there is obvious tendency for digitalization. With modern control systems, the process of running through gears and checking electronic solenoids is automated. One single system runs many different vehicle and transmission types.

If a transmission stops working because of a sensor, harness, connector or solenoid, it will be visually shown on the screen, explicitly as to identify this failure. Comprehensive data on each sensor can be compared against the benchmark result and thus it will be easy to determine whether that particular sensor is good or bad.

Multiple fluid pressure gauges enable thorough shift timing evaluation and adjustment. Controller box ordinarily comes for 8 pressure sensors with quick fit connectors. This can be expanded to 2x times (total 16 pressure sensors) if this happens to be required in the technological process. Readout in modern dynos is easy to adjust for any needs – especially if the software is appropriate for client-specific demands.

Importance of hardware with transmission dyno stands

Modern advanced dyno stands allow control and full testing of electronically shifted Mechatronic gearboxes and valve bodies. The importance of hardware for such dynos cannot be understated.

Modern dyno stands provide complete computerized control and with that extremely precise test procedures are easy to repeat. Some companies like Axiline concentrate on the US domestic market. However, the range of supported gearboxes is typically large: the dynos fit most USA home and non-national RWD, FWD, transverse, and Continuously-Variable Transmission gearboxes. These dyno stands check:

  • gearbox line pressure,
  • TC lockup and downshift,
  • shift point and response,
  • stall speed, and more.

At this, emulated load conditions for vehicles are applied and speed and load are measured with potentiometers. Transmission rebuilders will be able to confidently spot ATF and pressure leakages, check controls of the systems and hydraulics, and perform minor corrections with the gearbox still being mounted on the tester.

Reliability of hardware and flexibility of software are equally important for efficient use of transmission dynos.

Hardware is the brain of a transmission test stand. You do not have to be an IT-specialist to know to value enduring components that will serve to last for years and that will be protected from any electric malfunction.

In many cases, a physical body of the transmission dyno is still able to last for years, however, the hardware or the controller itself is very obsolete and cannot meet demands of those new development that have come by recently. When looking for such an advanced tool, it is also vital to look into this aspect of the equipment – how is it going to be supported after a couple of years of operation.

For instance, the most-professionally done Chinese dynos are looking really good, but the hardware part here is just a contribution and doesn’t bear any advantages. Axiline (at PowerTest) has quit updates for their controller system and just go with what had been on for many years now.

A good option to look into are companies that supply controller systems separately form the dyno testers. This means that they are concerned about all the aspects of the equipment: physical, hardware, software – and can deliver a lasting product. Hydra-Test’s HTC-S is adaptable for existing dynos from former years. If the machine has served years and is still functioning well, it can be easily refitted with a new controller box – enhancing the functions and data validation and processing.

For instance, among transmission dyno users from the USA and Europe there is often a situation when their current system is obsolete and shows the following deficiencies:

  1. Difficult process of programming new units.
  2. Inability to smoothly ramps solenoid current.
  3. No support for newer developments that came into market after 2020.
  4. Absence of reliable tech support from the manufacturer.
  5. Current transmission controller being no longer in production.

A new controller generation tackles these issues quite successfully and relatively easy. If you happen to be negotiating with a particular company’s manager, ask all of those questions upfront. New controller systems ideally have to come in a modular format when it is possible to build up a controller from several modules facilitating the support and any future upgrades.

New units coming to the market can be controlled efficiently with adaptability and flexibility of software. Ask your supplier if it is possible to write your own test scripts, this feature may be hidden but is pivotal for efficient use of transmission dynos.

Interpolation feature allows for solenoid ramp up, and with ease. New developments like Mercedes 722.6 or latest Chrysler models (like 68RFE) are supported equally with older designs.

Technical support is pivotal here. You do not want to be stuck with a fault that your supplier cannot be resolved for you. Large transmission equipment companies or companies coming from non-European countries oftentimes have these issues.

As an important note, remember that mechatronics have a different testing method and a 3 rd party supplier of equipment cannot have OEM access codes. Their use is restricted and protected. Therefore, do not expect that your transmissions can be tested along with their mechatronics components. It is simply not the case.

Mechatronics are excluded from the testing circuit with universal transmission dynos. They are tested separately by individual OEM tools – like ZF Testman and the like for other OEM’s. Double- or triple-check it if your potential supplier promises to supply mechatronics testing with their equipment.

Importance of software with transmission dyno stands

The IT field is on the rise and its advancements have also concerned the pretty much conservative transmission repair industry. When considering a transmission dyno, check for the following factors:

  • Date of software release
  • Frequency of software updates
  • Ease of update installations
  • Presence of online tech support
  • Possibility of desk sharing sessions (for example, via TeamViewer)
  • Flexibility of operational algorithms and their adjustments to clients’ needs
  • Convenience of output data readout and printing out
  • Attractive and user-friendly design

In fact, the software factor oftentimes goes without notice but it plays an essential role in efficacy of the dyno system. Just imagine running your high tech tool on Windows XP when it is 2020’s. This discriminates the whole investment.

Major suppliers

Nowadays, it is easy to commerce internationally and the suppliers are not limited to their local markets. US companies supply to Europe and to Turkey, Chinese suppliers have clients in the Middle and Near East. European suppliers have clients all across the globe – from Mexico to New Zealand. A certain group of suppliers works chiefly for the post-USSR countries.

1. Power Test

Active since: 1970s

Location: Wisconsin, USA

Types of equipment supplied: transmission dyno test stands, engine dynos, chassis dynos, valve body test stands, torque converter repair equipment, and other (all via different brands – Axiline, AIDCO, TCRS)

About: on the market for over 40 years, Power-Test has been providing test equipment to both manufacturers and rebuilding facilities and distributors in various field of industry. These include mining, oil & gas, power generation, and particularly military applications, marine, and construction.

Product updates: not recently.

Power Test has been acquiring local USA companies under one hood and is the largest company producing these types of products in the world. At that, the most powerful products are by AIDCO as they are for military applications. Test stands for transmission shops come as contributing to overall Power-Test profile.


2. RayTech (Guangzhou Ray Technology Solutions)

Active since: 2010s

Location: Guangzhou, China

Types of equipment supplied: transmission dyno test stands, valve body test stands, torque converter repair equipment, and transmission parts.

About: Some Chinese suppliers cannot be counted on, simply because of how they present their product. RayTech is different in these terms although their web presence is also a little unclear to a European or American potential buyer. They also take part in certain expos across the globe.

Product updates: new test plates for RayTech equipment.

Raytech is probably a most recognizable supplier of transmission equipment (along with a Chinese company TranSpeed). Despite having a good portfolio and attempts to position their products, some proper online presence could be improved. This supplier may be best to be contacted via Chinese local trading platform.

3. HYDRA-TEST (Cottingham Engineering LTD)

Active since: 1990s

Location: Kettering, United Kingdom (head office) / Minsk, Belarus (daughter production company)

Types of equipment supplied: transmission dyno test stands, valve body test stands, torque converter repair equipment, valve body repair tools.

About: at this day, Hydra-Test is the only prominent and reliable transmission repair equipment supplier from the United Kingdom. In 2019, the company opened a subsidiary production office to be more competitive in terms of product production cost and be able to deliver most reliable support quality. Valve Body testers by Hydra-Test are known for durability and full coverage of clients’ demands. Hydra-Torque equipment fabricated in the Belarusian division since 2017 has been supplied to various countries, including a heavy-duty application. The team is also open for custom-built solutions and delivers them in exact match to clients’ needs.

Product updates: Hydra-Dyno (launch of transmission dyno production), HTC-S (newest controller generation), 0AM valve body test tool.

ThisUK supplier is well-known for their attitude, constant update of available solutions. Opening a production site in Belarus is also an advancement. Some companies from post-Soviet territories can be barely counted on. However, if guided by European service standard, it is a great combination of affordable price and highest quality of transmission repair.


4. Mustang AE

Active since: 1970s

Location: Ohio, USA

Types of equipment supplied: dyno test stands for a huge variety of applications (including transmission dynos), solenoid testers.

About: on the market for over 40 years this company has launched a series of equipment for various applications, including military sector, heavy-duty equipment, and more. The company aspires to deliver creative thinking to drive continued success. They are one of the leaders in delivering sophisticated dynamometer technologies and advanced engineering capabilities.

Product updates: not recently.

Mustang AE’s growth has been hindered recently but it is a supplier worth referring to at least for comparison. A company with such a serious portfolio that includes emission measurement system fabrication, own design services bureau and more is certain to work on transmission repair clients’ requirements in a diligent way.

5. Extra:

We tried to contact alternative Chinese and USA suppliers to provide more info for consideration here but were treated with silence or an awkward invitation to come to China to see the machine and learn about pricing.