Vacamatic

Vacamatic

The 1941 M4 Vacamatic transmission by Chrysler was, historically, the first semi-automatic transmission which was marketed by a major manufacturer. It was an attempt to compete against rival's automatic transmissions, though it still had a clutch, primarily to change range. In normal driving, the clutch is not used. The transmission itself was a fully synchronised manual type, with four forward gears, one reverse; where the shifting was done 'automatically' by either vacuum cylinders (early, M4), or hydraulic cylinders (late, M6, Presto-Matic). The main difference was the addition of a fluid coupling between engine and clutch, and the shifting mechanism.

Operation

The range selector (looked like a column shift) had three positions: Low, High, and Reverse. Low consisted of what would be first and second gear with an ordinary four speed; High was third and fourth. Reverse was single ratio. Driving one was/is quite different: Upon starting, one would disengage the clutch, then choose a ratio (High for normal driving), and, whilst stopped with foot on the brake, engage the clutch. Pressing the accelerator would move you forward, in third, with the fluid coupling connecting the engine to the transmission. Upon reaching 15-20 mph, the accelerator is lifted, a 'clunk' would ensue (the automatic shift), and you would continue in fourth gear. Low range was quite similar, but much slower speeds. It is possible to start in Low, allow the shift, then move the range selector to High, using the clutch, and continue in High. This allowed somewhat faster acceleration, but was quite clumsy. Kickdown for passing was possible through electrical connections made by flooring the accelerator, though only in one range (ie: fourth to third).

Commentary

Never a performance transmission, it was nevertheless fine behind the six or eight cylinder flathead engine but once the V8 Hemi engine was introduced, the shortcomings of such a slow-shifting transmission were magnified greatly. Over the years, though, this transmission has acquired a reputation for absolute reliability.

ee also

* Fluid Drive
* List of Chrysler transmissions

References


Wikimedia Foundation. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • Semi-automatic transmission — Transmission types Manual Sequential manual Non synchronous Preselector Automatic Manumatic Semi automatic Electrohydraulic …   Wikipedia

  • Fluid Drive — is the trademarked name that Chrysler Corporation assigned to a transmission driveline combination offered from 1939 through 1953 in Chryslers and Desotos, and from 1939 through 1954 in Dodge models. The fluid drive element was a hydraulic… …   Wikipedia

  • Presto-Matic — Infobox Automobile name=M6 aka=Presto Matic Tip Toe Shift Gyro Matic Fluid Matic Fluidtorque Gyrotorque manufacturer=Chrysler Corporation production=1946 ndash;1953 class=2 speed manual with overdrive and torque converter predecessor=M4 Vacamatic …   Wikipedia

  • M4 — or M 4 may refer to:In computers: *m4 (computer language), a macro processing language *GNU m4, the GNU version of the m4 language In firearms and military equipment: *M4 Carbine, an assault rifle *M4 Sherman, the primary tank used by the… …   Wikipedia

  • Chrysler New Yorker — Manufacturer Chrysler Corporation Production 1939–1996 Successor Chrysler LHS …   Wikipedia

  • Chrysler Saratoga — The Chrysler Saratoga was a full sized automobile produced by the Chrysler Division of the Chrysler Corporation. Chrysler first used the Saratoga nameplate on its 1939 models and continued to use the name through to 1952. The name was used again… …   Wikipedia

  • Chrysler Newport — Manufacturer Chrysler Corporation Production 1940–1941 1949–1950 1961–1981 Predecessor DeSoto Adventurer …   Wikipedia

  • List of Chrysler transmissions — Chrysler produces a number of automobile transmissions in house.Automatic* 1941 ndash;1942 M4 Vacamatic/Simplimatic mdash; 4 speed semi automatic * 1946 ndash;1953 M6 Presto Matic mdash; 4 speed semi automatic with Fluid Drive (aka Tip Toe Shift …   Wikipedia

  • Автоматическая коробка переключения передач — Разрез гидротрансформаторной восьмиступенчатой АКП автомобиля Lexus. Разрез шестиступ …   Википедия

  • Механическая коробка переключения передач — Четырёхступенчатая МКПП TopLoader автомобиля фирмы Ford …   Википедия

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”