DEXRON
DEXRON is the trade name for a group of technical specifications of automatic transmission fluid created by General Motors. The name is a registered trademark of GM, which licenses the name and specifications to companies which manufacture the fluid and sell it under their own brand names. Not all Dexron fluids are licensed for reselling under another brand name. All licensed Dexron fluids must have a license number that begins with the letters B through J. If no license number or "Dexron Approved" logo is found on the container, the fluid may not be GM approved and the fluid cannot be guaranteed to meet GM specifications. GM, like many automobile manufacturers, uses transmissions sourced from other suppliers or transmission manufacturers around the world; these transmissions are not manufactured by GM. Many of these automatic transmissions use unique fluids that might not be shown on this page.
Originally the DEXRON name was associated exclusively with automatic transmission fluids, later GM released DEXRON gear oils and other lubricants under the DEXRON brand.
GM Automatic Transmission Fluids (ATF)
The original Dexron transmission fluid was introduced on April 1, 1967. Over the years, the original Dexron was supplanted by Dexron-II, Dexron-II, Dexron-II, Dexron-III, Dexron-III, Dexron-III, Dexron-VI, Dexron HP, Dexron LV ATF HP, and Dexron ULV which is the latest fluid. GM has upgraded the Dexron specifications over the years; the newer fluids are not always backward compatible with previous fluids. Newer 6, 8, 9, and 10-speed transmissions as well as Plug-In Hybrid, and Electric Vehicle transmission technologies require specialized fluids to operate properly. There remains a market for older fluids that claim to meet the earlier fluid specifications. See the details below for backward compatibility of each fluid.Before DEXRON – 1937–1967
1937 – Motor Oil
The Automatic Safety Transmission was first offered as an extra cost option by the Oldsmobile Division of GM in the fall of 1937 for their Six and Eight models. It was only used during the 1938 and 1939 model years. The Automatic Safety Transmission used the same seasonal grade of motor oil as the engine for lubrication and hydraulic functions.The Automatic Safety Transmission was a 4-speed transmission providing full-power shifting without the need for a conventional clutch. The transmission was called the Automatic Safety Transmission because the clutch operation was reduced to one-third of that required by a conventional transmission. The clutch was only necessary when starting or stopping the car.
The AST had two driving ranges. In low range, the transmission would shift from 1st to 2nd gear and then hold in 2nd. In High range, the transmission would start in 1st gear, jump to 3rd, then shift to 4th gear. The driver could change ranges with a flick of a finger.
1939 – Hydra-Matic Drive "Fluid"
Released in 1939, the 1940–1949 GM Hydra-Matic Drive was used by the Oldsmobile, Cadillac, and Pontiac divisions. The Hydra-Matic Drive used a specialized lubricant called GM Transmission Fluid No. 1. By using the term "Fluid" rather than "Oil" they hoped to discourage the previously accepted practice of using S.A.E 20 engine oil. This fluid was composed of a Group 1 base oil and additives to reduce oxidation, foaming, rust, corrosion, varnish, and sludge build-up. This was the world's first automatic transmission fluid designed for the world's first mass-produced automatic transmission.This fluid had cold weather performance problems which led to the need for an improved fluid; the Type "A" fluid in 1949. The Hydra-Matic drive fluid was only available at GM dealerships. As a result, regular S.A.E. 20 engine oil was being used in its place at filling stations and repair garages. Engine oil was only approved as a temporary fill fluid and led to transmission problems.
1949 – Type "A" Fluid
In 1949, General Motors established an Automatic Transmission Fluid Committee. The GM ATF committee established fluid specifications and a qualification procedure to eliminate the unsatisfactory fluids and at the same time provide the car owner with a means of identifying qualified fluids. The GM ATF Committee released a new Type "A" fluid specification. GM partnered with the Armor Research Foundation for fluid and qualification testing. Fluids that met the GM qualification requirements were issued an Armor Qualification license number of AQ-ATF-xxx. Example. The license number had to be displayed on the fluid container. As a result, qualified GM automatic transmission fluid was made available at retailers and service garages everywhere.From 1949–1951 there were only two licensed fluids:
- GM Type "A" Automatic Transmission fluid License No. AQ-ATF-101
- Texaco Texamatic Fluid Type "A" License No. AQ-ATF-102.
It is important to understand that every automatic transmission produced by any vehicle manufacturer used motor oil or the GM Type "A" transmission fluids from 1949–1958.
In 1950 Ford released their 1951 Fordomatic 3-speed transmission; it used the GM Type "A" fluid. In 1952 Chrysler released their 1953 Powerflite 2-speed transmission; it also used the GM Type "A" fluid.
This fluid was first used in the following transmissions:
- 1948 Buick Dynaflow 2-Speed Semi-Automatic Transmission
- 1950 Chevrolet Cast Iron Powerglide 2-Speed Semi-Automatic Transmission
- 1953 GM Dual Range Hydra-Matic 4-Speed Automatic Transmission
- 1953 Chevrolet Powerglide 2-Speed Automatic Transmission
- 1953 Buick Dynaflow 2-Speed Automatic Transmission
- 1956 Buick Dynaflow 2-Speed Automatic Transmission
- 1956 GM Controlled Coupling Hydra-Matic 4-Speed Automatic Transmission
- 1957 Chevrolet Turboglide 3-Ratio Automatic Transmission
- 1957 Buick Flightpitch Dynaflow 3-Ratio Automatic Transmission
1957 – Type "A" Suffix "A" Fluid
In 1959, Ford released their own automatic transmission fluid specification and stopped using GM fluid specifications. Also in 1959, Toyota released their Toyoglide 2-speed transmission; it used the GM Type "A" Suffix "A" fluid.
This fluid was first used in the following transmissions:
- 1961 GM Roto-Hydra-Matic 3-Speed Automatic Transmission
- 1961 Buick Dual Path 2-Speed Automatic Transmission
- 1962 Chevrolet Aluminum Powerglide 2-Speed Automatic Transmission
- 1964 GM Hydra-Matic 400 3-Speed Automatic Transmission
- 1966 GM Hydra-Matic 425 3-Speed Automatic Transmission
DEXRON fluids
1967 – DEXRON(B)
Released April 1, 1967. The original Dexron fluid better retained the initial properties of the previous Type "A" Suffix "A" fluid. Dexron was composed of a more stable, less reactive, hydrotreated Group 1 base oil plus additives for add non-foaming action qualities, high heat resistance, and anti-oxidation. This was the first GM ATF to advertise 24,000 miles between changes.This was the first GM ATF to require red dye as an aid in fluid leak detection. Prior to this fluid, GM ATF was the same color as engine oil. Aftermarket ATF was available with red dye.
GM Dexron licensed products have a license number on the container that begins with the letter B. Example: B10001. This fluid is backward compatible with all Type "A" Suffix "A", and the Type "A" fluids produced from 1949–1966.
This fluid was first used in the following transmissions:
- 1969 GM Hydra-Matic 180 3-Speed Automatic Transmission
1973 – DEXRON-II(C)
Dexron-II was composed of a more stable, less reactive, hydrocracked Group 2 base oil plus a revised additive package with corrosion and rust inhibitors such as Jojoba oil; however, the additive package caused problems with corrosion-prone solder in a relatively small number of GM's transmission fluid coolers. After discovering the corrosion problem, GM updated the fluid specification again and released Dexron-II in 1975.
GM Dexron-II licensed products have a license number on the container that begins with the letter C. Example: C-20109. This was the first GM ATF to advertise 50,000 miles between changes. This fluid is backward compatible with all previous Dexron fluids as well as the Type "A" Suffix "A", and the Type "A" fluids produced from 1949–1966.
1975 – DEXRON-II(D)
In 1975, GM released the Dexron-II specification. Dexron-II was composed of Group 2 base oil plus an additive package with alternative corrosion and rust inhibitors. The revised corrosion and rust inhibitors made the new fluid hygroscopic, which, while it was not a major problem in automatic transmissions, made Dexron II unsuitable for other hydraulic systems in which it was commonly used. GM Dexron-II licensed products have a license number on the container that begins with the letter D. Example: D-20002. This fluid is backward compatible with all previous Dexron fluids as well as the Type "A" Suffix "A", and the Type "A" fluids produced from 1949–1966.As a result of the 1973 OPEC Oil Embargo and fuel shortages, the U.S. government created the Corporate Average Fuel Economy regulations in 1975. The regulations were to be fully implemented by the 1978 model year. The automotive industry responded by changing to three typically unused transmission technologies:
- A 4th gear
- A Torque Converter Clutch
- Front Wheel Drive
This fluid was first used in the following transmissions:
- 1976 GM Hydra-Matic 200 3-Speed Automatic Transmission
- 1976 GM Hydra-Matic 250 3-Speed Automatic Transmission
- 1978 GM Hydra-Matic 325 3-Speed Transaxle w/TCC
- 1979 GM Hydra-Matic 125 3-Speed Transaxle w/TCC
- 1982 GM Hydra-Matic 200-4R 4-Speed Transmission w/TCC
- 1983 GM Hydra-Matic 700-R4 4-Speed Transmission w/TCC
- 1984 GM Hydra-Matic 440-T4 4-Speed Transaxle w/TCC
1990 – DEXRON-II(E)
Electronic control of shift pattern, shift timing, shift quality, line pressure, and TCC apply and release rates were all affected by cold temperature performance of the ATF flowing through solenoids.
In 1990, Dexron-II was released. Dexron-II was composed of Group 2 base oil plus an additive package. According to the GM Technical Service Bulletin: 92-7-2 issued Oct-2-1991, DEXRON-II has better anti-foaming characteristics, improved low-temperature flow characteristics, and improved high-temperature oxidation stability. This fluid's low temperature performance was also improved.
GM Dexron-II licensed products have a license number on the container that begins with the letter E. Example: E20001. This fluid is backward compatible with all previous Dexron fluids as well as the Type "A" Suffix "A", and the Type "A" fluids produced from 1949–1966.
This fluid was first used in the following transmissions:
- 1991 GM Hydra-Matic 4L80-E
- 1993 GM Hydra-Matic 4L60-E 4-Speed, electronically controlled transmission.
- 1993 GM Hydra-Matic 4T60-E 4-Speed, electronically controlled transaxle.
1993 – DEXRON-III(F)
Dexron-III underwent a number of iterations in an attempt to address various shortcomings but was eventually replaced by new thinking i.e. DEXRON-VI. GM Dexron-III licensed products have a license number on the can that begins with the letter F. Example: F-30001. This fluid is backward compatible with all previous Dexron fluids as well as the Type "A" Suffix "A", and the Type "A" fluids produced from 1949–1966.
In 1994–1995, some early OBD-II phase-in vehicles experienced a P0300 DTC. Engineers determined that road forces being transferred through the TCC were affecting the normal rotational fluctuations of the crankshaft and tricked the ECM into thinking there was a cylinder misfire.
The solution was to create a new kind of TCC that would normally slip around 35 rpm. GM called it the Variable Capacity Converter Clutch, other manufacturers had their own names. Some VCCC systems had a shudder or vibration during normal operation. Engineers tried several computer calibration changes, but a revised fluid was also needed to address the issue.
Ford released the new Mercon V Fluid Specification in 1996, GM released the Dexron-III Fluid Specification in 1998, and Chrysler released the MS-9602 Change C Fluid Specification in 1999.
This fluid was first used in the following transmissions:
- 1997 GM Hydra-Matic 4T65-E 4-Speed transaxle with Variable Capacity Converter Clutch.
1998 – DEXRON III(G)
GM Dexron-III licensed products have a license number on the can that begins with the letter G. Example: G-30001. This fluid is backward compatible with all previous Dexron fluids as well as the Type "A" Suffix "A", and the Type "A" fluids produced from 1949–1966.
2003 – DEXRON III(H)
Introduced in 2003, GM's Dexron III specification replaced III. The is an additive package for an updated friction modifier and with an oxidatively stable base oil. Oils according to this specification have longer maintenance of friction properties and anti-shudder properties, better foam control and a longer fluid life. Universal for all automatic transmission with and without controlled torque converter lockup clutch, the so-called GKÜB for gear-clutch-lock.GM Dexron-III licensed products prior to 2011 had a license number on the can that begins with the letter H. Example: H-30001.
NOTICE: This fluid specification and licensing program was Inactivated March 2011. The ATF Type III fluid shown in the photograph is ACDelco's non-licensed fluid which is used to support older transmissions which still required the Dexron-III fluid. This fluid is backward compatible with all previous Dexron fluids as well as the Type "A" Suffix "A", and the Type "A" fluids produced from 1949–1966.
2005 – DEXRON-VI(J)
In a joint venture, Ford and GM collaborated on the development of a new 6-speed FWD transaxle. Both companies would share the designs and build their own transmissions. The design of these transmissions required a new fluid.In 2005, Ford released the Mercon Low Viscosity fluid and GM released the Dexron VI specification. The fluid specification for Dexron-VI was first used as the GM factory-fill automatic transmission fluid for the model year 2006. Roy Fewkes, GM Powertrain Staff Project Engineer and Chairman of the GM
ATF/Driveline Lubricants Approval Committee patented the new Dexron-VI fluid composition under US Patent US8642519B2
Dexron VI is of a slightly lower viscosity when new compared to the prior Dexron fluids, but the allowed viscosity loss from shearing of the ATF during use is lower for Dexron VI, resulting in the same lowest allowed final viscosity for both Dexron III and VI in test. In reality most of the DEXRON-III fluids typically sheared to about 4.2 cSt in use. The lower, more stable viscosity improved pumping efficiency within the transmission and fluid stability over life. Since Dexron VI is not allowed to thin out as much as Dexron III during use, it requires the use of higher-quality, more shear-stable formulations. The container rear label reads "Full Synthetic Automatic Transmission Fluid"; however, the base oil composition is not stated. The current GM specification that defines the fluid is GMW16444, which superseded the original specification, GMN10060.
All Dexron-III licenses expired permanently at the end of 2011, and GM now supports only Dexron-VI fluids for use in their older automatic transmissions. Aftermarket fluids asserted by their manufacturers to meet Dexron-III and earlier standards continue to be sold under names such as Dex/Merc. These fluids are not regulated or endorsed by GM.
GM Dexron-VI licensed products have a license number on the container that begins with the letter J. Example: J-60301. This was the first GM ATF to advertise 100,000 miles between changes for "Normal Driving" conditions and 50,000 miles for "Severe Service". This fluid is backward compatible with Dexron-III and Dexron-III fluids only.
This fluid was first used in the following transmissions:
- 2007 6T70/6T75 Transaxles
- 2007 6L80 Transmission
2013 – DEXRON-HP
There have been two versions of this fluid specification
- In July 2013, GM released the Low Viscosity Dexron-HP Fluid Specification. As shown on the photograph of the rear panel, the 2013 Dexron HP is composed of a group 4 Polyalphaolefin Base oil and additives provided by the Afton Chemical Corporation. The rear panel label of early containers of this fluid incorrectly state that this fluid is backward compatible with previous Dexron ATF, it is not. The label was corrected on later bottles of the fluid.
- In May 2017, A revision was made to the GMW16974 fluid specification. A change to a Group III+ base oil rather than a group 4 PAO base oil was made as well as another additive package option from Afton Chemical Corporation.
This fluid was first used in the following transmissions:
- 2015 8L90, 8L45, 8-speed RWD/4WD vehicles
- 2017 1ET25 Chevrolet Bolt EV drive unit
- 2018 9T50 9-Speed FWD/AWD transaxle
2014 – DEXRON-ULV
This transmission and the transmission fluid specification was co-developed by Ford and GM. The current specification that defines the fluid is FORD WSS-M2C949-A. This fluid is also marketed as Mercon ULV.
IMPORTANT: The quart containers of Dexron ULV must be shaken to stir up the additives before pouring. This fluid is not backward compatible with any previous fluids.
This fluid was first used in the following transmissions:
- 2017 10L90 10-Speed Automatic Transmission
2016 – Mobil 1 Synthetic LV ATF HP "Black Label"
Dexron LV ATF HP is made by Mobil and is marketed as Mobil 1 LV ATF HP. Dexron LV ATF HP is composed of a Poly-alpha-olefin Group IV Base oil and additives developed by Afton Chemical needed for the proper operation of the 2015 and above GM 8L90 8-Speed rear wheel drive automatic transmission. The current GM specification that defines the fluid is GMW16974.
2016 – DEXRON III(K) for Manual Transmissions
On August 1, 2016, GM released the Dexron III fluid specification as a fluid to support older GM manual transmissions and power steering systems requiring the previously discontinued Dexron-III fluid.WARNING:The additive package for automatic transmissions has been removed from this fluid; do not use it in any automatic transmission.
2018 – Mobil 1 Synthetic LV ATF HP "Blue Label"
On October 1, 2018, a special fluid specification was introduced for a revised "Dexron Approved" Mobil 1 Synthetic LV ATF HP. This revised fluid was introduced in GM Technical Service Bulletin 18-NA-355 in December of 2018. The revision is to help correct a torque converter clutch shudder in the GM 8L90 and 8L45 automatic transmissions after a complete flush of the system.Dexron LV ATF LV is made by Mobil and is marketed as Mobil-1 LV ATF HP. Mobil-1 LV ATF HP is composed of a Gas to liquids Group 3+ Base oil and additives developed by Infineum needed for the proper operation of the 2015 and above GM 8L90 and 8L45 8-Speed rear wheel drive automatic transmission.
IMPORTANT: Containers of this fluid have a revised blue and silver label on the front of the container. This "Dexron Approved" Dexron HP product has a J-62120 license number on the rear label of the container.
GM "Lifetime" ATF
Sealed Transmissions
Any automatic transmission fluid will last longer if the transmission case could be hermetically sealed, but transmissions typically have two potential entry points for air:- The Dipstick Tube. Any transmission with a dipstick tube has the potential to let additional oxygen into the transmission through a dipstick that is not fully seated in the tube, or dipstick tube plug that is not fully seated. Even the process of checking the fluid level with a dipstick can allow additional oxygen and dirt into the transmission. Many modern transmissions do not have a dipstick, they have sealed transmission fluid level check plugs instead. By removing the traditional dipstick, the transmission manufacturer has also removed a potential entry point for oxygen; this reduces the potential for fluid oxidation. A sealed transmission will typically have longer transmission fluid life than a non-sealed transmission.
- The Transmission Vent. Transmissions need vents to compensate for internal air pressure changes that occur with fluctuating fluid temperatures and fluctuating fluid levels during transmission operation. Without those vents, pressure could build resulting in seal and gasket leaks. Before the use of better quality base oil in ATF in the late 1990s, some older transmission breather vents contained a Transmission Air Breathing Suppressor valve to prevent oxygen and water ingestion into their transmissions. Oxygen reacts with high temperature transmission fluid and can cause oxidation, rust, and corrosion. Automatic transmission fluids using lower quality base oil oxidized more easily than fluids using higher quality base oils. GM, and other transmission manufacturers now use smaller, remote mounted, breather vents specially designed to keep out water, but allow the a small amount of air movement through the breather as necessary.
Sealed ATF Containers
- Use Sealed Containers. Containers storing automatic transmission fluid should always be sealed; if exposed to the atmosphere, ATF may absorb moisture and potentially cause shift concerns.
- Use New Fluid Only. When performing repairs on ATF equipped transmissions, it is important to use only new, clean ATF when refilling the transmission. Never reuse ATF.
Example maintenance schedule
The definition of 'Lifetime Fluid" differs from transmission manufacturer to transmission manufacturer. Always consult the vehicle maintenance guide for the proper service interval for the fluid in your transmission and your driving conditions.
Chevrolet Colorado Example: According to the Scheduled Maintenance Guide of a 2018 Chevrolet Colorado with "Lifetime Fluid" could have two different fluid service intervals depending upon how the vehicle is driven:
1. Normal Driving
- Carry passengers and cargo within recommended limits on the Tire and Loading Information label
- Driven on reasonable road surfaces within legal driving limits.
2. Severe Driving
- Mainly driven in heavy city traffic in hot weather
- Mainly driven in hilly or mountainous terrain
- Frequently towing a trailer
- Used for high speed or competitive driving
- Used for taxi, police, or delivery service.
Aftermarket Automatic Transmission Fluids
For over 70 years, the oil aftermarket has produced both licensed, and non-licensed, formulations of automatic transmission fluids. Today, aftermarket fluids asserted by their manufacturers to be compatible for use in General Motors automatic transmissions continue to be sold under names such as Dexron/MERCON, Multi-Purpose, and Multi-Vehicle fluids. Non-licensed fluid are typically less expensive; however, these fluids are not regulated or endorsed by GM for use in their transmissions. Vehicle manufacturer approved and licensed fluids must have the license number printed on the product information label of the container or on the container housing. Non-Licensed fluids do not show a license number. Make sure the fluid to be installed into a transmission matches the recommended fluid in the specifications section of the vehicle's owner's manual.Mislabeled or Misleading Labeling on ATF Containers
ATF which has been mislabeled, has misleading labeling, or is fraudulently bottled as another product is an ongoing problem. Some of these fluids have led to multiple transmission failures. The three organizations shown below are trying to stop this problem in the United States.- United States Laws: The U.S. Department of Commerce, National Institute of Standards and Technology, Handbook 130 2019 Edition, contains Uniform Laws and Regulations in the Areas of Legal Metrology and Fuel Quality. Section IV.G.3.14 defines laws regulating the Labeling and Identification of Transmission Fluid. Paragraph IV.G.3.14.1.1. Container Labeling. reads The label on a container of transmission fluid shall not contain any information that is false or misleading.
- California Laws: The State of California has developed additional Laws in an attempt to prevent mislabeled and misleading labeling. Statutes: California Business and Professions Code, Division 5, Chapters 6, 14, 14.5, and 15. Regulations: California Code of Regulation, Title 4, Division 9, Chapters 6 and 7.
- American Petroleum Institute Monitoring: The American Petroleum Institute maintains a list of invalid labeling of petroleum products. This real-time list includes motor oils and ATF.