Honda has long built nearly all of its own automobile transmissions, unlike many other automobile manufacturers which often source transmissions from external sources. [1] The most notable exception was in 2014, when Honda decided to forgo an in-house designed transmission and chose the ZF 9HP transmission for their Acura TLX V6 model, later extending the offering of the ZF transmission to the Acura MDX, Odyssey, Pilot and Ridgeline. [2] However, there have been reports of problems with ZF transmissions and Acura recalled its 2015 TLX models. ZF has attributed most of these problems to software issues.
Most of Honda's automatic transmissions are unusual in that they do not use planetary gears like nearly all other makers, however, Honda has recently introduced (2017) an all-new, in-house designed 10-speed automatic that uses planetary gears. Honda's older transmissions such as the Hondamatic semi-automatic transmission and its successors use traditional, individual gears on parallel axes like a manual transmission, with each gear ratio engaged by a separate hydraulic clutch pack. This design is also noteworthy because it preserves engine braking by eliminating a sprag between first and second gears. Instead of a sprag or roller clutch, Honda's older transmissions rely on pressure circuits to modulate line pressure to change gears. [3]
Honda was forced to invent their new system due to the vast array of patents on automatic transmission technology held by BorgWarner and others.
Honda initially chose to integrate the transmission and engine block for its first application (in the N600) as in the Mini. The Hondamatic incorporated a lockup function, which Honda called a third ratio, and had manual gear selection. The company's early transmissions also used a patented torque converter which used stator force to reduce hydraulic losses by using a reaction arm to increase the hydraulic pressure when the stator was stalled. The reaction arm acted directly on the regulator valve; this meant that increased pressure was available to the clutch plates when torque multiplication was greatest. The stator was equipped with a sprag clutch enabling it to freewheel when required. The N360/N600 controlled gear changes by balancing a throttle valve and a centrifugal valve. These "opposing" pressures caused the gear changes through the free-floating gear change valves.
On October 18, 1967, the N360 AT model with the lock-up function was unveiled at the London Auto Show.(ref Honda Worldwide) It is not now clear if the lockup function made it into production; it was not fitted to the N600AT for Europe.
The typical torque converter of the time was about 11.5in. long and the torque multiplication ratio was about 1.5 to 1. The N360/N600 torque converter was about 5.5in. long and achieved a torque multiplication of over 2.2 to 1.
The first Civic was equipped with a manually changed hydraulically engaged two-speed transmission with a torque converter. This torque converter was nominally about 7in. and achieved a torque multiplication of c2.7 to 1. It also used the reaction arm on the stator as in the N360/N600 to increase hydraulic pressure. It was initially announced in Europe as an automatic as the staff at Honda in Europe assumed that it would like the N600 to be fully automatic. This was quickly changed to "Hondamatic". This gearbox was a separate unit and used ATF - Automatic Transmission Fluid.
The company's naming scheme is also confusing, as it is specific to a single model of the vehicle and some identifiers are reused. Below is a list of Honda automatic transmissions: [4]
Acura is the luxury and performance division of Japanese automaker Honda, based primarily in North America. The brand was launched on March 27, 1986, marketing luxury and performance automobiles. Acura sells cars in the United States, Canada, Mexico, Panama, and Kuwait. The company has also previously sold cars in Mainland China, Hong Kong, Russia, and Ukraine. Plans to introduce Acura to the Japanese domestic market in the late 2000s did not eventuate due to the financial crisis of 2007–2008.
The Acura TL is a car that was manufactured by Acura, the North American luxury division of Honda. It was introduced in 1995 to replace the Acura Vigor and was badged for the Japanese-market from 1996 to 2000 as the Honda Inspire and from 1996 to 2004 as the Honda Saber. The TL was Acura's best-selling model until it was outsold by the MDX in 2007. In 2005, it ranked as the second best-selling luxury sedan in the United States behind the BMW 3 Series, but sales decreased after the 2008 model year. Four generations of the Acura TL were produced, with the final fourth generation TL premiering in 2008 as a 2009 model and ending production in 2014, when it was replaced together with the TSX by the TLX.
The Acura MDX is a mid-size luxury crossover SUV with three-row seating produced by the Japanese automaker Honda under its luxury Acura division since 2000. The alphanumeric moniker stands for "Multi-Dimensional" luxury. It has ranked as the second-best selling mid-size luxury SUV after the Lexus RX in the U.S.
A semi-automatic transmission is a multiple-speed transmission where part of its operation is automated, but the driver's input is still required to launch the vehicle from a standstill and to manually change gears. Semi-automatic transmissions were almost exclusively used in motorcycles and are based on conventional manual transmissions or sequential manual transmissions, but use an automatic clutch system. But some semi-automatic transmissions have also been based on standard hydraulic automatic transmissions with torque converters and planetary gearsets.
The Honda Legend is a series of V6-engined executive cars that was produced by Honda between 1985 and 2021, and served as its flagship vehicle. The Legend has also been sold under the Acura Legend, RL and RLX nameplates — the successive flagship vehicles of Honda's luxury Acura division in North America from 1986 until 2020.
The Honda Pilot is a mid-size crossover SUV with three-row seating manufactured by Honda since 2002. Primarily aimed at the North American market, the Pilot is the largest SUV produced by Honda. Pilots are currently manufactured in Lincoln, Alabama, and the Pilot was produced in Alliston, Ontario until April 2007. The first generation Pilot was released in April 2002 as a 2003 model.
The J-series is Honda's fourth production V6 engine family introduced in 1996, after the C-series, which consisted of three dissimilar versions. The J-series engine was designed in the United States by Honda engineers. It is built at Honda's Anna, Ohio, and Lincoln, Alabama, engine plants.
Variable Cylinder Management (VCM) is Honda's term for its variable displacement technology, which saves fuel by using the i-VTEC system to disable one bank of cylinders during specific driving conditions—for example, highway driving. The second version of VCM (VCM-2) took this a step further, allowing the engine to go from 6 cylinders, down to 4, and further down to 3 as the computer sees fit. The most recent version of VCM (VCM-3) reverted to the previous 3- and 6-cylinder operation.
The Acura RDX is a compact luxury crossover SUV produced by Acura, a luxury vehicle division of Honda, as the second crossover SUV offering from the brand after the mid-size MDX. Since it was introduced, it shared its platform with the Honda Civic and CR-V.
The Hondamatic was Honda's first semi-automatic transmission. It was produced from 1973 through 1988. The Hondamatic name continued to be used on fully-automatic transmissions from Honda.
The H5 is Honda's first 5-speed automatic transmission.
Advanced Compatibility Engineering is the marketing name given to an automobile body structure design by Honda. It claims to distribute collision energy evenly and redirect it away from the passenger compartment, while at the same time, minimizing damage to other impacted vehicles. This is accomplished by using numerous grades of steel which crumple in key areas and remain rigid in others. It is standard on all Honda and Acura models as of the 2017 model year.
Super Handling-All Wheel Drive (SH-AWD) is a full-time, fully automatic, all-wheel drive traction and handling system, which combines front-rear torque distribution control with independently regulated torque distribution to the left and right rear wheels. This way the system freely distributes the optimum amount of torque to all four wheels according to the driving conditions. The system was announced in April 2004, and was introduced in the North American market in the second generation 2005 model year Acura RL, and in Japan as the fourth generation Honda Legend.
A dual-clutch transmission (DCT) is a type of multi-speed vehicle transmission system, that uses two separate clutches for odd and even gear sets. The design is often similar to two separate manual transmissions with their respective clutches contained within one housing, and working as one unit. In car and truck applications, the DCT functions as an automatic transmission, requiring no driver input to change gears.
9HP is the trademark name for the ZF Friedrichshafen nine-speed automatic transmission models for transverse engine applications, designed by ZF's subsidiary in Saarbrücken and built in Gray Court, South Carolina. It is used in front-wheel drive and all-wheel drive vehicles.
The Acura ILX is a compact car (C-segment) manufactured and marketed by Honda under the Acura brand, based on the ninth-generation Civic sedan. The ILX replaced the Canadian market exclusive Acura CSX. The gasoline-electric hybrid version was Acura's first.
The Acura RLX is a mid-size flagship luxury car manufactured by Honda and sold under their Acura division, released in 2013, succeeding the RL. The RLX was discontinued in 2020.
The Acura TLX is a four-door entry-level luxury sedan sold by Acura, a luxury division of Honda, since 2014. It is the successor to both the TL and TSX models. As of 2021, the discontinuation of the RLX leaves the TLX as the flagship sedan in Acura's lineup.