Transaxle
A transaxle is a single mechanical device which combines the functions of an automobile's transmission, axle, and differential into one integrated assembly. It can be produced in both manual and automatic versions.
Engine and drive at the same end
Transaxles are nearly universal in all automobile configurations that have the engine placed at the same end of the car as the driven wheels: the front-engine/front-wheel drive; rear-engine/rear-wheel drive; and mid-engine/rear-wheel drive arrangements.
Many mid- and rear-engined vehicles use a transverse engine and transaxle, similar to a front-wheel drive unit. Others use a longitudinal engine and transaxle like Ferrari's 1989 Mondial t which used a "T" arrangement with a longitudinal engine connected to a transverse transaxle. Front-wheel drive versions of modern Audis, from the A4 upwards, along with their related marques from the Volkswagen Group (which share the same automobile layout) also use a similar layout, but with the transaxle also mounted longitudinally.
The front-wheel drive Renault 16 had a longitudinal engine and transaxle, with the engine behind the transaxle. The transaxle case was designed to allow the final-drive ring gear to be on either side of the pinion; this allowed the engine-transaxle assembly to be used in the rear-wheel drive Lotus Europa, which had the engine in front of the transaxle (i.e., mid-engined).
Front-engine, rear-wheel drive transaxles
Front-engine, rear-wheel drive vehicles tend to have the transmission up front just after the engine, but sometimes a front engine drives a rear-mounted transaxle. This is generally done for reasons of weight distribution, and is therefore common on sports cars. Another advantage is that as the driveshaft spins at engine speed it only has to endure the torque of the engine, instead of that torque multiplied by the 1st gear ratio. This design was pioneered in the 1934 Škoda Popular, and then in the 1950 Lancia Aurelia, designed by Vittorio Jano.
Since this placement of the gearbox is unsuitable for a live axle (due to excessive unsprung mass), the rear suspension is either independent, or uses a de Dion tube (notably in Alfa Romeos). Rare exceptions to this rule were the Bugatti T46 and T50 which had a three speed gearbox on a live axle.
The Nissan GT-R and Ferrari FF (and its successors) are unusual in being all-wheel-drive cars with front-engined layouts and rear-mounted transaxles. In the Nissan, one driveshaft sends power to the transaxle (which also contains the 'center' differential) and another driveshaft sends power back along the car to the front wheels. In the Ferrari, the rear transaxle works in the conventional manner, whilst the drive to the front wheels comes from a separate gearbox at the front of the engine.
Notable Front-engine, rear-wheel drive layout vehicles with a transaxle design include:
- 1898–1910 De Dion Bouton
- 1914–1939 Stutz Bearcat
- 1929–1936 Bugatti Type 46
- 1934–1944 Škoda Popular
- 1950–1958 Lancia Aurelia
- 1951–1956 Pegaso Z-102
- 1957–1970 Lancia Flaminia
- 1959–1963 DAF 600
- 1961–1963 Pontiac Tempest
- 1964–1968 Ferrari 275
- 1963–1968 Ferrari 330
- 1968–1973 Ferrari 365 GTB/4 "Daytona"
- 1972–1987 Alfa Romeo Alfetta and GTV6
- 1976–1988 Porsche 924
- 1976–1991 Volvo 300 series
- 1977–1985 Alfa Romeo Giulietta (116)
- 1978–1995 Porsche 928
- 1982–1995 Porsche 944 and Porsche 968
- 1984–1987 Alfa Romeo 90
- 1985–1992 Alfa Romeo 75/Milano
- 1989–1991 Alfa Romeo SZ/RZ
- 1992–2003 Ferrari 456
- 1996–2005 Ferrari 550/Ferrari 575M
- 1997–2004 Chevrolet Corvette C5
- 1997–1999 Panoz Esperante GTR-1
- 1997–2002 Plymouth Prowler
- 1998–2005 Shelby Series 1
- 2001-2007 Maserati Coupé and Spyder
- 2003–date Aston Martin DB9
- 2004–2009 Cadillac XLR
- 2004–2013 Chevrolet Corvette C6
- 2004–2011 Ferrari 612 Scaglietti
- 2004–2012 Maserati Quattroporte
- 2005–date Aston Martin V8 Vantage
- 2006–2012 Ferrari 599 GTB Fiorano
- 2007–2010 Alfa Romeo 8C Competizione
- 2007–date Maserati GranTurismo/GranCabrio
- 2008–date Ferrari California/California T
- 2009–2012 Lexus LF-A
- 2010–date Aston Martin Rapide
- 2010–2013 Mercedes-Benz SLS AMG
- 2011–2016 Ferrari FF
- 2012–date Aston Martin Vanquish
- 2017–date Ferrari F12berlinetta
- 2014–date Chevrolet Corvette C7
- 2014–date Mercedes-AMG GT
Rear-engine, rear-wheel drive transaxles
Volkswagen and later Porsche made extensive use of transaxles in their rear (and mid) engined vehicles. Over the years, models adopting this configuration have included:
- 1921–1925 Rumpler Tropfenwagen
- 1938–2003 Volkswagen Beetle
- 1940–1945 Volkswagen Kübelwagen (Type 82)
- 1941–1944 Volkswagen Schwimmwagen (Type 166)
- 1948–1965 Porsche 356
- 1950–1990 Volkswagen Type 2 T1-T3
- 1955–1974 Volkswagen Karmann Ghia
- 1960–1969 Chevrolet Corvair [1]
- 1961–1973 Volkswagen Type 3
- 1963–1976 Hillman Imp
- 1963–present Porsche 911
- 1964–1969 Škoda 1000 MB
- 1965–1969, 1976 Porsche 912
- 1967-1973 Lamborghini Miura
- 1968–1974 Volkswagen Type 4
- 1969–1976 Porsche 914 (mid-engined)
- 1969–1980 Škoda 100, Škoda 110 R
- 1971-1978 Maserati Bora
- 1971-1992 De Tomaso Pantera
- 1975–1989 Porsche 930
- 1976–1990 Škoda 105, Škoda 120, Škoda 130, Škoda Garde, Škoda Rapid (1984)
- 1981–1983 DeLorean
- 1984-1988 Pontiac Fiero (mid-engined)
- 2013–present Praga R1 (mid-engined)
Four-wheel drive
All Audi cars with longitudinal engines and their 'trademark' quattro four-wheel drive (4WD) system, along with their related marques from the Volkswagen Group which share the same layout, utilise a transaxle. This is mounted immediately behind the front-mounted engine (again, longitudinally) and contains the 'gearbox' (manual, automatic, DSG, or CVT), along with both the centre differential, and the front differential and final drive unit.
Other 4WD applications include:
- 1979-2002 Volkswagen Vanagon/Caravelle Syncro Edition - rear-engined, transaxle in the front;
- 1984–1986 Ford RS200 – mid-engined, with the gearbox in the front;
- 1989-2001 Mitsubishi 3000GT - front-engined, gearbox (transmission, front and centre differential) in the front;
- 2007–on Nissan GT-R – front-engined, gearbox in the rear.
See also
References
- "GM Heritage: The First Corvair". History.gmheritagecenter.com. Retrieved 2017-05-24.
