What is the basic function of an automatic transmission?

This is a component of the drive system that automatically changes gear ratios, eliminating the need to operate the clutch and gear shift.

How is DSG different from a classic automatic gearbox?

DSG (Direct-Shift Gearbox) is a double-clutch gearbox that works faster and smoother than classic hydraulic transmissions.

What does Tiptronic mean?

Tiptronic is a type of automatic transmission that allows manual gear selection while maintaining full automatic operation.

What are the symptoms of automatic transmission failure?

The most common are: jerking when changing gears, delayed response, unusual noises or transmission oil leaks.

Are automatic transmissions economical to operate?

Modern gearboxes, such as the 8-speed ZF installed in BMW and Audi, reduce fuel consumption by 10–15% compared to older designs.

Which models does the Sprinter 906 gearbox fit?

The most commonly used gearboxes were 722.6 and 722.9, compatible with 2.1 CDI, 2.7 CDI and 3.0 CDI units in the years 2006–2017.

How to check if the gearbox fits the car?

The best method is to compare the OEM number or use the VIN number – this guarantees full compatibility with the drive system.

Automatic gearboxes

At Global Parts, we offer a wide selection of original used car parts, including automatic transmissions for many popular car brands such as BMW, Mini, Mercedes, Audi, Volkswagen, and others. Our automatic transmissions undergo quality control to ensure you receive a top-quality product.

More information

Make

Category

Subcategory

Condition

In Stock

Price

Fuel type

Gearbox type

Products in promotion

Part no. 9455022

BMW X1 F48 X2 F39 20dX Mini F60 B47D Automatic Gearbox GA8Y45HW 9455022 WARRANTY

Product currently unavailable

Part no. A1662709102

Mercedes GLE W166 250d 4Matic Automatic Gearbox 725038 725.038 A1662709102

Product currently unavailable

Part no. A2212701501

Automatic Gearbox Mercedes W205 W212 W221 722904 722.904 2212701201 WARRANTY

Product currently unavailable

Part no. 8662686

BMW F20 F21 LCI 116d Diesel B37 Automatic Auto Gearbox 8652603 GA8HP50Z WARRANTY

Product currently unavailable

Part no. 9454415

BMW X1 F48 X2 F39 Mini F60 Dual Clutch Gearbox 9454415 7DCT300 - AMJ WARRANTY

Product currently unavailable

Part no. 7593731

BMW X1 E84 23dX N47S Automatic Gearbox GA6HP19Z 7593731 WARRANTY

Product currently unavailable

Part no. A9062703600

Mercedes Sprinter W906 Automatic Gearbox 722686 722.686 A9062703600 WARRANTY

Product currently unavailable

Part no. A2042701606

Mercedes W204 C63 W212 E63 AMG Automatic Gearbox 722930 A2042701606 WARRANTY

Product currently unavailable

Part no. 7640056

BMW X3 F25 20dX N47N Diesel Automatic Gearbox 7640056 GA8HP45X WARRANTY

Product currently unavailable

Part no. A2032704500

Mercedes W203 C 200 220 CDI 2.2 5 Speed Automatic Gearbox 722699 WARRANTY

Product currently unavailable

Part no. A0034460310

Mercedes W212 722.902 Mechatronics Control Unit Automatic Gearbox A0034460310

Product currently unavailable

Part no. A2122708408

Automatic Gearbox Mercedes W204 C207 W212 722995 722.995 A2122707208 WARRANTY

Product currently unavailable

Part no. 7592493

BMW E90 E91 335i N54 Automatic Gearbox 7592493 7576162 7572062 GA6HP19Z WARRANTY

Product currently unavailable

Part no. 7590136

BMW E60 E61 LCI 525d M57N2 Automatic Gearbox GA6HP19Z 7590136 WARRANTY

Product currently unavailable

Part no. A7252700511

Mercedes SLK R172 Automatic Gearbox 725008 725.008 A1722707900 WARRANTY

Product currently unavailable

Seat Leon FR 5F 2.0 TDI CUNA DSG Automatic Gearbox PUJ 0D9300041Q WARRANTY

-15%

Part no. 0D9300041Q

Seat Leon FR 5F 2.0 TDI CUNA DSG Automatic Gearbox PUJ 0D9300041Q WARRANTY

Product currently unavailable

Part no. A2112704202-3

Mercedes W204 W211 W212 Automatic Gearbox 722902 722.902 A2072700400 WARRANTY

Product currently unavailable

Part no. A1712709600

Mercedes W203 W204 W211 W212 CL203 Automatic Gearbox 722906 A2112702701 WARRANTY

Product currently unavailable

Part no. 0BK300039E

Audi A8 D4 4H 3.0 TDI CDTA Quattro Automatic Gearbox NXU 0BK300039E WARRANTY

Product currently unavailable

Part no. 7647288

Automatic Gearbox BMW F10 525d F20 125d F30 325d N47S1 GA8HP45Z 7647288 WARRANTY

Product currently unavailable

Part no. A2463705403

Mercedes C117 W176 Automatic Dual Clutch Gearbox 724016 A2463704703 WARRANTY

Product currently unavailable

Part no. 3541050061

Lexus LS400 Mechatronics Control Unit Automatic Gearbox 4FC ATM 35410-50061

Product currently unavailable

Part no. 7601932

Automatic Gearbox BMW F07 GT F10 F11 530d N57 GA8HP70Z 7601932 WARRANTY

Product currently unavailable

Part no. 8632223

BMW X5 F15 X6 F16 Oil Pump Automatic Gearbox GA8HP75Z N57Z N57X 0501327294

Product currently unavailable

Part no. A2463704002

Mercedes C117 W176 AMG 4Matic Automatic Gearbox 724015 A2463704002 WARRANTY

Product currently unavailable

Part no. 0GC300044F

Seat Ateca FR 2.0 TDI DFFA Automatic Gearbox 7 Speed DSG UAX 0GC300044F WARRANTY

Product currently unavailable

Part no. 8650892

Automatic Gearbox BMW F20 LCI F30 F31 118d 316d B47 8650892 GA8HP50Z WARRANTY

Product currently unavailable

Part no. 7647856

Mechatronics BMW E81 E87 LCI E90 E91 E92 E93 GA6HP19Z Drive Automatic Gearbox

Product currently unavailable

Part no. 9810011

Mini Cooper S N18 ALL4 R60 R61 Auto Automatic Gearbox GA6F21WA 9810011 WARRANTY

Product currently unavailable

Part no. A2112704202-2

Mercedes W204 W211 W212 Automatic Gearbox 722902 722.902 A2042703702 WARRANTY

Product currently unavailable

Part no. A2463704003

Mercedes W176 4Matic Automatic Dual Clutch Gearbox 724011 A2463705303 WARRANTY

Product currently unavailable

Part no. 7630575

BMW X5 E70 LCI X6 E71 30dX N57 Automatic Auto Gearbox 7630575 GA8HP70X WARRANTY

Product currently unavailable

Part no. 8687818

Mechatronics Automatic Gearbox BMW F10 F11 535d F13 640d N57Z GA8HP70Z 8687818

Product currently unavailable

Part no. A2182700201

Automatic Gearbox Mercedes W204 W211 W212 722903 722.903 A2182709300 WARRANTY

Product currently unavailable

Part no. 7638575-1

Mini Cooper One R55 R56 LCI N16 Automatic Gearbox GA6F21WA ANF 7593890 WARRANTY

Product currently unavailable

Part no. A2463707202-1

Mercedes W176 W246 Automatic Dual Clutch Gearbox 724020 A2463707202 WARRANTY

Product currently unavailable

Part no. 0B5300056B

Audi A4 B8 A5 8T 2.0 TFSI CDNC Quattro Automatic Gearbox NRW 0B5300056B WARRANTY

Product currently unavailable

Part no. 8632185

Mechatronics BMW X5 F15 X6 F16 N57Z N57X Drive Automatic Gearbox GA8HP75Z

Product currently unavailable

Part no. 8685420-1

Automatic Gearbox BMW F45 F46 220dX B47 GA8F22AW 8685420 WARRANTY

Product currently unavailable

Part no. 8744940

Automatic Gearbox BMW G30 G31 530dX G32 630dX B57 GA8HP75X 8744940 WARRANTY

Product currently unavailable

Part no. A1712707100

Mercedes W203 W204 W211 W212 CL203 Automatic Gearbox 722906 A1712706400 WARRANTY

Product currently unavailable

Part no. A1712709600-1

Mercedes R171 W204 W212 Automatic Gearbox 722906 722.906 1712703500 WARRANTY

Product currently unavailable

Part no. A2463708602

Mercedes W176 W246 Automatic Dual Clutch Gearbox 724003 A2463705800 WARRANTY

Product currently unavailable

Part no. 7537895

BMW E60 E61 525i M54 Automatic Auto Gearbox GA6HP19Z 7537895 WARRANTY

Product currently unavailable

Part no. 4H1927158CL

Audi A8 D4 3.0 TDI Automatic Gearbox Transmission Mechatronics NWJ 4H1927158CL

Product currently unavailable

Part no. 7630579

Automatic Gearbox BMW Z4 E89 18i 20i 28i Petrol N20 7630579 GA8HP45Z WARRANTY

Product currently unavailable

Part no. 0B5300060P

Audi Q5 8R 2.0 TDI Quattro Automatic Gearbox S-Tronic PWX 0B5300060P WARRANTY

Product currently unavailable

Part no. 52108574AA

Automatic Gearbox Jeep Commander Grand Cherokee 3.0 CRD DGE 722678 WARRANTY

Product currently unavailable

Part no. 9810013-1

Automatic Gearbox Mini Cooper D SD R60 R61 ALL4 2.0 GA6F21WA 9810013 WARRANTY

Product currently unavailable

Part no. A2512701101

Mercedes R320 W251 OM642 4Matic Automatic Gearbox 722.902 2512703300 WARRANTY

Product currently unavailable

Part no. 8742500

BMW F30 335dX F32 435dX LCI N57Z Automatic Gearbox GA8HP70X 8742500 WARRANTY

Product currently unavailable

VW Touareg Audi Q7 4L Cayenne 9PA 3.0 TDI Automatic Gearbox 09D300039E WARRANTY

-15%

Part no. 09D300039E

VW Touareg Audi Q7 4L Cayenne 9PA 3.0 TDI Automatic Gearbox 09D300039E WARRANTY

Product currently unavailable

Part no. 0AM300060A

Volkswagen Polo 6R V 1.4 TSI CAVE Automatic Gearbox DSG NAY 0AM300060A WARRANTY

Product currently unavailable

Part no. A7252709710

Mercedes GLE C292 350 D Automatic Gearbox 725035 725.035 A1662707202 WARRANTY

Product currently unavailable

Part no. 7853540-1

BMW F80 M3 F82 F83 M4 Twin Clutch Gearbox Drivelogic GS7D36SG 7853533 Damaged

Product currently unavailable

Part no. A2122708008

Automatic Gearbox Mercedes W204 W212 W221 722908 722.908 A2122708009 WARRANTY

Product currently unavailable

Part no. LR029745

Land Rover Range Rover L320 3.0 D Automatic Gearbox CH227000AC 8HP-70 WARRANTY

Product currently unavailable

Part no. A2112704202-4

Mercedes W204 W211 W212 Automatic Gearbox 722902 722.902 2042700921 WARRANTY

Product currently unavailable

Part no. 2231P9

Citroen Dispatch 9H07 9HM Diesel Manual Gearbox 5 Speed DP75 2231P9 WARRANTY

Product currently unavailable

Part no. 5A131B8

BMW F20 F21 LCI F30 F31 LCI F32 Automatic Gearbox Mechatronics GA8HP50Z 5A131B8

Product currently unavailable

Part no. 7590130

BMW 5 Series E60 E61 LCI 520d N47 Automatic Gearbox GA6HP19Z 7590130 WARRANTY

Product currently unavailable

Part no. 0AW300048H

Audi A6 C7 2.0 TDI Automatic Gearbox Transmission PCF 0AW300048H WARRANTY

Product currently unavailable

Part no. 7636111

BMW F10 F11 530d N57N Automatic Gearbox Transmission GA8HP70Z WARRANTY

Product currently unavailable

Part no. A2052706501

Automatic Gearbox Mercedes W204 W205 W212 722908 722.908 2052705501 WARRANTY

Product currently unavailable

Part no. 8609131

E-Transmission Gearbox BMW i3 I01 Hybrid 60Ah Rex 8609131 GE1B131H WARRANTY

Product currently unavailable

Part no. A2122707503

Mercedes W204 W212 W221 Automatic Gearbox 722908 722.908 A2122705204 WARRANTY

Product currently unavailable

Part no. 7581411

BMW E60 E61 LCI 525d M57N2 Automatic Gearbox GA6HP19Z 7581411 7577610 WARRANTY

Product currently unavailable

Part no. 8617113

BMW X3 F25 20dX Diesel N47N Automatic Gearbox GA8HP45X 7623367 WARRANTY

Product currently unavailable

Audi Q3 8U 2.0 TFSI CULB Quattro Automatic Gearbox DSG RBW 0BH300012R WARRANTY

-15%

Part no. 0BH300012R

Audi Q3 8U 2.0 TFSI CULB Quattro Automatic Gearbox DSG RBW 0BH300012R WARRANTY

Product currently unavailable

Part no. A2212706501

Mercedes W212 W221 S500 Automatic Gearbox 722904 722.904 2212705401 WARRANTY

Product currently unavailable

Part no. 0B5300055T

Audi A7 4G 3.0 TDI Quattro Automatic Gearbox NPB 8 Speed 0B5300055T WARRANTY

Product currently unavailable

Part no. 0D9300020G

Volkswagen Golf Mk7 GTI 2.0 TSI CHHA Automatic Gearbox QSQ 0D9300020G WARRANTY

Product currently unavailable

Part no. A2122706109

Automatic Gearbox Mercedes W204 C207 W212 722908 722.908 A2122704409 WARRANTY

Product currently unavailable

Part no. 7590133

BMW E81 E87 E90 E91 E92 E93 120d 320d N47 Automatic Gearbox GA6HP19Z WARRANTY

Product currently unavailable

Part no. 7609179-1

Automatic Gearbox Mini R56 R55 Cooper D Diesel W16 7565553 GA6F21WA ANC WARRANTY

Product currently unavailable

Part no. 7606392

BMW X5 E70 4.8i N62N Automatic Gearbox Transmission 7567790 GA6HP26Z WARRANTY

Product currently unavailable

Mercedes W203 W204 W211 W212 C209 Kompressor Automatic Gearbox 722695 WARRANTY

-15%

Part no. A2112703300

Mercedes W203 W204 W211 W212 C209 Kompressor Automatic Gearbox 722695 WARRANTY

Product currently unavailable

Part no. 02E300012G

Audi TTS 8J 2.0 TFSI CDLB Quattro Automatic Gearbox DSG LRK 02E300012G WARRANTY

Product currently unavailable

Part no. 7630949

Automatic Gearbox BMW X1 E84 18dX 20dX Diesel N47 GA6HP19X 7630949 WARRANTY

Product currently unavailable

Part no. 0CW300049M

Audi A3 8V 1.0 TFSI CHZD S-Tronic Automatic Gearbox RQL 0CW300049M WARRANTY

Product currently unavailable

Part no. 8601209

BMW F20 F21 M135i N55 Petrol Automatic Gearbox 8601209 GA8HP45Z WARRANTY

Product currently unavailable

Porsche Cayenne 92A 3.0 TDI Automatic Gearbox NAD 8 Speed 0C8300037H WARRANTY

-15%

Part no. 95830001113

Porsche Cayenne 92A 3.0 TDI Automatic Gearbox NAD 8 Speed 0C8300037H WARRANTY

Product currently unavailable

Part no. A2212709803

Mercedes W204 W212 W221 Automatic Gearbox 722903 722.903 A2212709803 WARRANTY

Product currently unavailable

Part no. A2463704802

Mercedes C117 GLA X156 W176 W246 Mechatronics Automatic Gearbox A2463704802

Product currently unavailable

Part no. 09L300040S

Audi S4 B7 4.2 BBK Quattro Automatic Gearbox Transmision JTR 09L300040S WARRANTY

Product currently unavailable

Part no. A1242700402

Mercedes W124 Automatic Gearbox 722429 722.429 A1242700402 WARRANTY

Product currently unavailable

Part no. 8651264

Automatic Gearbox BMW F20 F30 F31 LCI 120dX 320dX B47 GA8HP50X 8651264 WARRANTY

Product currently unavailable

Part no. A1693702400-1

Mercedes W169 W245 A150 A160 B150 Automatic Gearbox 722801 21k miles WARRANTY

Product currently unavailable

Audi Q7 4L 3.0 TDI Quattro Automatic Gearbox NAC 8 Speed 0C8300037G WARRANTY

-15%

Part no. 0C8300037G

Audi Q7 4L 3.0 TDI Quattro Automatic Gearbox NAC 8 Speed 0C8300037G WARRANTY

Product currently unavailable

Part no. 7563294

BMW E60 E61 E90 E91 325i 525i Petrol N52 Automatic Gearbox Auto 6 Speed WARRANTY

Product currently unavailable

Part no. 8605538

Automatic Gearbox BMW F10 F11 F12 F13 535d 640d N57Z GA8HP70Z 8623408 WARRANTY

Product currently unavailable

Part no. 8617000

Automatic Gearbox BMW F10 F11 530d Diesel N57 GA8HP70Z 7602090 WARRANTY

Product currently unavailable

Part no. A1642707001

Mercedes ML W164 Automatic Gearbox 722902 722.902 1642706101 WARRANTY

Product currently unavailable

Part no. A2042703100

Mercedes W204 C209 W212 Automatic Gearbox 722999 722.999 A2042701300 WARRANTY

Product currently unavailable

Part no. A9062706800

Mercedes Sprinter W906 Automatic Gearbox 722908 722.908 9062703800 WARRANTY

Product currently unavailable

Part no. 7581583-1

BMW E60 E61 LCI 530d M57N2 Automatic Gearbox GA6HP26Z 7581583 7576114 WARRANTY

Product currently unavailable

Part no. 8637975

Manual Gearbox BMW F20 120i F30 320i LCI B48 GS6-17GG 8637975 WARRANTY

Product currently unavailable

Part no. 8605535

BMW F10 530d F30 F31 330d N57N Automatic Auto Gearbox GA8HP70Z 8623463 WARRANTY

Product currently unavailable

Part no. 0AM300060E

Audi A1 8X 1.4 TSI Automatic Gearbox Transmission DSG PMT 0AM300060E WARRANTY

Product currently unavailable

Showing 298-396 of 608 products

Top-class automatic transmissions – smooth driving in all conditions

Innovative solutions in automatic transmissions - reliability that gives you an advantage on the road

Automatic transmissions are technologically advanced drivetrain components that provide smooth gear changes without the need for manual operation. They make driving more comfortable and efficient, both in city traffic and on long journeys. At Global Parts, you'll find a wide selection of used car parts, including automatic transmissions, ideal for BMW , Audi , Mercedes , Volkswagen , Mini, and more. According to a detailed definition, an automatic transmission (AT) is a set of planetary gears, hydraulic clutches, a torque converter, and a control module (mechatronics). Its function is to automatically select gear ratios, which contributes to smooth driving and optimizes fuel consumption. Transmissions include conventional (hydraulic), CVT (continuously variable), DSG/S tronic (dual-clutch), and Tiptronic (with manual gear shifting).

What functions do automatic transmissions perform?

Automatic transmissions are complex devices that perform key functions in a vehicle's drive system: Automatic gear shifting – The gearbox automatically adjusts the gear ratios to driving conditions, ensuring optimal use of engine power. Improved driving comfort – Smooth gear changes eliminate the need for manual operation of the clutch and gear shift. Fuel economy – Modern automatic transmissions adjust gear ratios to optimize fuel consumption. Cooperation with other vehicle systems – The automatic transmission cooperates with safety systems such as ESP and cruise control, increasing stability and driving comfort. Examples of applications:

In the Mini Cooper R50 5-speed Multitronic automatic transmissions were used, which allowed for smooth driving in city traffic.
Mercedes Sprinter 906 was equipped with NAG1 (722.6) and 7G-Tronic (722.9) gearboxes, depending on the CDI engine version.
IN Audi A6 Quattro 6- and 8-speed Tiptronic gearboxes were often installed, matched to four-wheel drive.

Why is it worth taking care of automatic transmissions ?

Malfunctioning or neglected automatic transmission maintenance can lead to serious problems with the vehicle's drivetrain. Typical symptoms include: Jerky shifting – This may indicate problems with the torque converter or transmission oil wear. Delays in shifting gears – Indicates possible damage to the mechatronics or hydraulic components of the gearbox. Noise and vibration – Mechanical problems in the gearbox can cause disturbing noises during operation. Gearbox Oil Leaks – Leaks in the gearbox can lead to reduced performance and serious damage. At Global Parts, we offer genuine used automatic transmissions that have undergone extensive quality testing, ensuring their durability and reliability.

Comparison table of popular automatic transmission types

Box type	Number of gears	Application (examples)	Characteristic
Classic AT	4–10	BMW, Mercedes, Audi	Durable, universal, used since the 1990s
DSG / S tronic	6–7	Audi, VW	Dual-clutch, very fast gear changes
CVT	Stepless	Mini, Nissan, Honda	Smooth acceleration, no classic gears
Tiptronic	5–8	Audi A6 Quattro, VW Passat	Automatic with manual selection option

How to choose the right automatic transmission ?

When choosing automatic transmissions, there are several key aspects to pay attention to: Vehicle-specific fit – Each drivetrain has its own specific technical requirements. At Global Parts, you'll find automatic transmissions perfectly matched to BMW , Audi , Mercedes , Volkswagen , Mini , and more . Technical condition – Used gearboxes should be free from mechanical damage and leaks, and their hydraulic and electrical components should be fully functional. Gearbox type – Select the appropriate gearbox type (classic automatic, CVT, DSG, Tiptronic) depending on the vehicle equipment. Compatibility can be confirmed by the vehicle's OEM number or VIN. For example, a 722.6 gearboxThe transmission used in the Sprinter 906 came in many variants, with different gear ratios and software. Therefore, matching it to the specific engine version and production year is always crucial.

Why choose used automatic transmissions ?

Used car parts , such as automatic transmissions, are a practical solution that allows you to save money while maintaining high quality. By choosing used automatic transmissions, you gain: Lower costs – Used crates are much cheaper than new ones, but offer just as high quality. Ecology – Recycling car parts supports environmental protection and reduces waste. A wide range – In our store you will find automatic transmissions for the most popular car brands.

How to take care of automatic transmissions ?

To ensure that automatic transmissions function reliably for a long time, it is worth following a few rules: Change the transmission oil and filters regularly according to the manufacturer's recommendations to ensure proper lubrication and cleanliness of the system. Avoid overloading the vehicle, especially when driving with heavy loads, to prevent the gearbox from overheating. Monitor any symptoms of malfunction, such as noises, vibrations or delays in gear shifting, and respond in a timely manner. If you need a replacement, you'll find the right used car parts at Global Parts that will restore full functionality to your drive system.

FAQ - most frequently asked questions about automatic transmissions

Question	Answer
What is the basic function of an automatic transmission?	This is a component of the drive system that automatically changes gear ratios, eliminating the need to operate the clutch and gear shift.
How is DSG different from a classic automatic gearbox?	DSG (Direct-Shift Gearbox) is a double-clutch gearbox that works faster and smoother than classic hydraulic transmissions.
What does Tiptronic mean?	Tiptronic is a type of automatic transmission that allows manual gear selection while maintaining full automatic operation.
What are the symptoms of automatic transmission failure?	The most common are: jerking when changing gears, delayed response, unusual noises or transmission oil leaks.
Are automatic transmissions economical to operate?	Modern gearboxes, such as the 8-speed ZF installed in BMW and Audi, reduce fuel consumption by 10–15% compared to older designs.
Which models does the Sprinter 906 gearbox fit?	The most commonly used gearboxes were 722.6 and 722.9, compatible with 2.1 CDI, 2.7 CDI and 3.0 CDI units in the years 2006–2017.
How to check if the gearbox fits the car?	The best method is to compare the OEM number or use the VIN number – this guarantees full compatibility with the drive system.

Summary: Automatic Transmissions at Global Parts Automotive Store

Automatic transmissions are technologically advanced components that ensure comfort and smooth driving in all conditions. By maintaining their technical condition, you can enjoy the reliability and efficiency of your vehicle for a long time. The Global Parts automotive store invites you to browse our wide selection of original used car parts . Whether you're looking for car parts for BMW , Audi , Volkswagen , Mercedes, Mini , and more, you'll find them at competitive prices. We strive to ensure every customer finds the right parts for their car, and if you have any questions or concerns about selecting the right components, we're happy to help! Please contact us – we're here to help! For more information and interesting facts, visit our automotive blog .

bmw car parts used car parts mini used car parts genuine parts mercedes genuine parts motor store genuine used audi parts bmw automatic transmission mercedes automatic transmission mini automatic transmission audi automatic transmission volkswagen automatic transmission