- Premiere 1961 in the W 111 and W 112 model series
- A milestone in 125 years of innovation
- The automatic transmission combines smooth gear-shifting with efficiency
“The ultimate driving experience,” proclaimed the brochure on the first automatic transmission developed in-house by Mercedes-Benz back in 1961. Several years of intensive development work went into the four-speed automatic clutch which was premiered in April 1961 as an optional extra for the 220 SEb model of the 111 series. The automatic transmission even featured as standard in the Mercedes-Benz 300 SE which was presented in August 1961. This opened a special chapter in the brand’s success story running through 125 years of the automobile.
Mercedes-Benz decided to build its own automatic transmission in keeping with the company’s commitment to maintaining its innovative strength – a constant factor throughout the brand’s history: as the automatically shifting transmission has a decisive influence on the character of an automobile, the development engineer striving for the best can only be content with a solution tailored precisely to the brand’s own vehicles.
Instead of a torque converter the new transmission had a hydraulic start-up clutch, which offered the advantage of reduced power loss. The secondary four-speed planetary gear system comprised two planetary sets, three multi-disc clutches and three band brakes.
Automatic gear-shifting in the history of Mercedes-Benz
Mercedes-Benz had already produced vehicles with partially automated gear shifting prior to this development. The model 770 (model series W 07), which went down in automotive history as the “Grand Mercedes,” featured semi-automatic vacuum-power shifting for the overdrive gear, for example. This function of the Maybach overdrive transmission was controlled via a lever on the steering wheel.
And while the Mercedes-Benz engineers were already at work on the company’s first automatic transmission, the “Hydrak” hydraulic automatic clutch was presented in the summer of 1957. The new automatic clutch was initially available as an optional extra for the 220 S and 219 models. The system comprised a hydraulic start-up clutch, a conventional single-plate dry clutch for engagement and disengagement during gear-shifting and a freewheel to bypass the hydraulic clutch.
Genuine automatic transmissions also emerged at this time, initially produced by external suppliers. From the autumn of 1955, Mercedes-Benz offered the model 300 c with a three-speed converter transmission from Borg-Warner, for example.
1961: the first automatic transmission from the inventor of the automobile
Mercedes-Benz introduced its first automatic transmission to be developed in-house on the model 220 SEb in April 1961. The automatic transmission came as an optional extra for this model, while featuring as standard on the model 300 SE of model series 112 which was presented in August 1961.
Further Mercedes-Benz models subsequently benefited from this refined, convenient and efficient transmission of the available engine power. From August 1962 the four-speed automatic transmission was available for the 220 and 220 S models subject to an additional charge of DM 1400, for example.
The four-speed automatic transmission was also optionally available for the Mercedes-Benz 230 SL Roadster (W 113) as of 1963 – a first among the sports cars from Mercedes-Benz. Finally, the prestigious Mercedes-Benz 600 limousine was available exclusively with the automatic transmission as of 1964.
75 years after Carl Benz invented the automobile, the launch of the automatic transmission marked a further milestone in the brand’s history and the starting point for an outstanding series of innovations. The engineering and technology relating to automatic gear-changing has been subject to ongoing development at Mercedes-Benz since 1961.
The automatic transmissions have been built at the Hedelfingen factory since November 1961. The 100,000th automatic transmission for passenger cars from Mercedes-Benz was produced here in 1966, the output subsequently topping 500,000 by 1971 and one million in 1975. This development provides a clear illustration of the automatic transmission’s success. The registration figures reveal a similar picture: by 1964, just three years after the automatic transmission from Mercedes-Benz was unveiled, 14.5 percent of all passenger cars delivered by the brand were fitted with this type of transmission, the figure even rising to over 20 percent when the petrol engines are considered on their own. This share rose continually, until automatic and transmissions each accounted for around 50 percent of delivered cars in the mid-1980s.