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.

Automatic/Semi-automatic transmissions

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]

Dual-clutch transmission

  • 2014– honda 8DCT 8-speed dual clutch automatic transmission with torque converter
  • 2014– 7-speed dual clutch Sequential SportShift automatic transmission
  • 2016– 9-speed dual clutch automatic transmission

Manual transmissions

  • 1979-1982 GK — 5-speed
    • Honda Prelude 1.8
  • 1986-1987 A2K5/A2K6 — 5-speed
    • Honda Prelude 2.0 Si
  • 1986 A1B2
    • Honda Prelude DX Carb
  • 1986-1987 A2Q5 — 5-speed
  • 1986-1987 A2Q6 — 5-speed
  • 1988 E2Q5 — 5-speed
  • 1988 E2Q6 — 5-speed
  • 1988-1991 L3 — 5-speed
  • 1988-1989 D2J5 — 5-speed
    • Honda Prelude Si
  • 1989 E2R5 — 5-speed
  • 1989 E2R6 — 5-speed
  • 1990-1991 D2A4 — 5-speed
    • Honda Prelude 2.0Si, Si, SR
  • 1992-1995 S20 A000 — 5-speed
  • 1992-1995 S20 B000 — 5-speed
  • 1996-2006 SEV — 5-speed?
    • Honda HR-V
  • 1997 S8G — 5-speed
    • Honda Integra (Japanese Domestic Market, ZC)
    • Honda CR-X del Sol Si & ESi (late model with D16Y8 engine)
  • 1997-1999 S20 B000 — 5-speed
    • Honda Civic coupe EX
  • 1998 S40 (E5F and P4A may be casting codes) — 5-speed
    • Honda Civic LX
  • 2004-2007 ATC6 — 6-speed
  • 2007-2008 SMJM — 5-speed
    • Honda Fit
  • 2009-2014 SP4M — 5-speed
    • Honda Fit
  • 2015-2017 S7A7 — 6-speed
    • Honda Fit

References

  1. ↑ Henry, Ian. "Shifting priorities". Automotive Manufacturing Solutions. Retrieved 18 December 2017.
  2. ↑ Duffer, Robert. "Honda lurches ahead with pesky 9-speed transmission". Chicago Tribune. Retrieved 18 December 2017.
  3. ↑ "Honda Transmission Repair – Royal Transmission". www.royaltransmissiondbn.com. Archived from the original on 2018-10-16.
  4. ↑ Honda Transmissions: List of Honda Transmissions, Hondamatic, Honda H4a Transmission, Honda H4 Transmission, Honda H5 Transmission, by General Books LLC, dated September 2010, ISBN 9781158398478
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