Hondamatic
| H2 | |
|---|---|
| Overview | |
| Manufacturer | Honda |
| Production | 1976–1979 |
| Body and chassis | |
| Class | 2-speed transverse automatic transmission |
| Chronology | |
| Successor | H3 |
| Transmission types |
|---|
| Manual |
| Automatic |
| Bicycle gearing |
- See also list of Honda transmissions for other Hondamatics
The Hondamatic (also called the H2) was Honda's first automatic transmission. It was produced from 1973 through 1979. The Hondamatic name is used on all automatic transmissions from Honda.
The original Hondamatic, like all following Honda automatics, featured sliding gears on parallel axes rather than planetary gears like most other automatic transmissions. The design preserved engine braking by eliminating a sprag between the first and second gears. Shifting between 1st and 2nd gears was done by simply sliding the gear selector from 1 to 2. It did not automatically shift, but because of the torque converter, could be driven entirely in 2nd gear. The Honda torque converter had a lockup, leading the company to sell the original Hondamatic (which had just two forward gear ratios) as a three-speed. The true three-speed H3 was launched in 1979.
Applications:
- 1973–1980 Honda Civic
- 1976–1979 Honda Accord
- 1979 Honda Prelude
History
Honda could not make a conventional planetary gearset automatic transmissions without infringing on any patents. Honda eventually asked Borg Warner to design a prototype transmission for their upcoming vehicles. However, Borg-Warner declined. This was due to Borg-Warner not having transmission specifications that was efficient enough for such a small engine like the 500cc Honda S500 and one that was able to be reliable at a maximum engine speed of 8000rpm. This lead Honda to design their own transmission. They purchased a transmission from Borg Warner for the purpose of developing an original transmission design. They tested their newly developed automatic transmission on the L700. When testing and refinements had been made, Honda sold their first automatic transmission in the N360.[1]
Motorcycle
The Hondamatic was later used in Honda's 400, 450 and 750 cc motorcycles. In this application, it was not a true automatic transmission, as the driver had to manually select one of the two gears, though Honda's torque converter meant that no clutch was needed.
Applications:
- CB750A (1976-1978)
- CB400A Hawk Hondamatic (1978)
- CM400A Hondamatic (1979-1981)
- CM450A Hondamatic (1982-1983)
Scooter, ATV, and power equipment
Honda also applies the Hondamatic name to a hydraulic piston-based continuously variable transmission used in motorscooters, all-terrain vehicles, and other types of power equipment.
Issues
When compared to planetary gearset transmissions, the Hondamatic design uses much smaller diameter clutches. When coupled with engines with high torque output, those clutches didn't have enough surface area to hold itself and therefore failed. This was evident on many transmissions that were coupled to V6 engines like the Honda Odyssey, Honda Accord, Acura TL and Acura MDX.