Engineering:Mercedes-Benz 9G-Tronic transmission

9G-Tronic
Overview
Manufacturer	Daimler AG
Production	2013–present
Body and chassis
Class	9-speed longitudinal automatic transmission
Chronology
Predecessor	Mercedes-Benz 7G-Tronic transmission

9G-Tronic is Mercedes-Benz's trademark name for its nine-speed automatic transmission, starting off with the W9A 700 (Wandler-9-Gang-Automatik bis 700 Nm Eingangsdrehmoment; converter-9-gear-automatic with 516 lb-ft maximum input torque; type 725.0) as core model.

Abstract

In all applications this transmission is identified as the New Automatic Gearbox Generation Three, or NAG3. Initially it debuted on the E 350 blueTEC in 2013, before launched in the Mercedes-Benz S-Class (W222). It has been expanded to be used in the Mercedes-Benz C-Class (W205) and the sedan and wagon variants of the Mercedes-Benz E-Class (W213). This transmission was later introduced on Mercedes-Benz M-Class (W166) facelift on the GLE 250 d model. V12 engine models continue to use the older Mercedes-Benz 7G-Tronic transmission. By the end of 2018 unsurpassed ratio span among longitudinal automatic transmissions for passenger cars.

It is also fabricated by Jatco for use in Nissan and Infiniti vehicles.

Specifications

Basic concept

Technical and economic progress is reflected in 9 forward gears out of 10 main components, compared to 7 forward gears out of 11 main components in the direct predecessor. It is fully electronic controlled. Torque converter lock-up can operate in all 9 forward gears.

Gear ratios

Gear Teeth and Ratios				Planetary Gearset: Teeth				Count	Total	Avg.
Model Type	First Delivery			Sun 1 [math]\displaystyle{ {S_1} }[/math] Ring 1 [math]\displaystyle{ {R_1} }[/math]	Sun 2 [math]\displaystyle{ {S_2} }[/math] Ring 2 [math]\displaystyle{ {R_2} }[/math]	Sun 3 [math]\displaystyle{ {S_3} }[/math] Ring 3 [math]\displaystyle{ {R_3} }[/math]	Sun 4 [math]\displaystyle{ {S_4} }[/math] Ring 4 [math]\displaystyle{ {R_4} }[/math]	Brakes Clutches	Ratio Span	Gear Step
Gear	1	2	3	4	5	6	7	8	9	R
W9A ALL 725.0	2013			46 98	44 100	36 84	34 86	3 3	9.1495	1.3188
Ratio	5.5032 [math]\displaystyle{ \tfrac{6,835}{1,242} }[/math]	3.3333 [math]\displaystyle{ \tfrac{10}{3} }[/math]	2.3148 [math]\displaystyle{ \tfrac{125}{54} }[/math]	1.6611 [math]\displaystyle{ \tfrac{299}{180} }[/math]	1.2106 [math]\displaystyle{ \tfrac{1,075}{888} }[/math]	1.0000 [math]\displaystyle{ \tfrac{1}{1} }[/math]	0.8651 [math]\displaystyle{ \tfrac{58,781}{67,944} }[/math]	0.7167 [math]\displaystyle{ \tfrac{43}{60} }[/math]	0.6015 [math]\displaystyle{ \tfrac{52,675}{87,576} }[/math]	- 4.9316 [math]\displaystyle{ -\tfrac{6,125}{1,242} }[/math]
W9A ALL 725.0	2016			46 98	44 100	37 83	34 86	3 3	8.9022	1.3143
Ratio	5.3545 [math]\displaystyle{ \tfrac{13,670}{2,553} }[/math]	3.2432 [math]\displaystyle{ \tfrac{120}{37} }[/math]	2.2523 [math]\displaystyle{ \tfrac{250}{111} }[/math]	1.6356 [math]\displaystyle{ \tfrac{3,631}{2,220} }[/math]	1.2106 [math]\displaystyle{ \tfrac{1,075}{888} }[/math]	1.0000 [math]\displaystyle{ \tfrac{1}{1} }[/math]	0.8651 [math]\displaystyle{ \tfrac{58,781}{67,944} }[/math]	0.7167 [math]\displaystyle{ \tfrac{43}{60} }[/math]	0.6015 [math]\displaystyle{ \tfrac{52,675}{87,576} }[/math]	- 4.7983 [math]\displaystyle{ -\tfrac{12,250}{2,553} }[/math]
Ratio odd	[math]\displaystyle{ \tfrac{(S_1 (S_2+R_2 ) + R_1 S_2 ) (S_3 + R_3 )}{S_1 (S_2+ R_2 ) S_3} }[/math]		[math]\displaystyle{ \tfrac{R_2 (S_3+ R_3 )}{(S_2+R_2 ) S_3} }[/math]		[math]\displaystyle{ \tfrac{R_2 R_4}{R_2 R_4- S_2 S_4} }[/math]		[math]\displaystyle{ \tfrac{R_4 (S_1 (S_2+R_2 ) + R_1 S_2 )}{S_1 R_4 (S_2+R_2 ) + R_1 S_2 (S_4+ R_4 )} }[/math]		[math]\displaystyle{ \tfrac{R_1 R_2 R_4}{(R_1 R_2 + S_1 (S_2+R_2 )) S_4+R_1 R_2 R_4} }[/math]
Ratio even · R	[math]\displaystyle{ \tfrac{S_3+ R_3}{S_3} }[/math]		[math]\displaystyle{ \tfrac{S_4 (S_3+R_3 ) + S_3 R_4}{S_3 (S_4+R_4 )} }[/math]		[math]\displaystyle{ \tfrac{1}{1} }[/math]		[math]\displaystyle{ \tfrac{R_4}{S_4+ R_4} }[/math]		[math]\displaystyle{ -\tfrac{R_1 R_2 (S_3 + R_3 )}{S_1 (S_2+R_2 ) S_3} }[/math]

Nomogram

Planetary gearSet 1 – Planetary gearSet 2 – Planetary gearSet 3 – Planetary gearSet 4

▶️ Interactive Nomogram

This nomogram is a real geometric calculator exactly representing the rotational speeds of the transmission's 3x4 = 12 internal shafts for each of its 9 ratios (+ reverse), grouped according to their 4 permanent coupling on 3 joint ordinates and 5 independent ordinates. These ordinates are positioned on the abscissa in strict accordance with the proportions of the sun gears' teeth numbers relative to those of their rings. Consequently, the output ratios on the 3rd ordinate (carrier of the third planetary gearset) follows closely those of the actual transmission. This advantageous geometric construction sets us free from Willis' famous and tedious formula, because all calculations are exclusively determined by lengths ratios, respectively teeth numbers on the abscissa for the 4 epicyclic ratios, and of rotational speeds on the 3rd ordinate for the 10 gear ratios.

Legend:
A : Brake (blocks s2 sun gear)
B : Brake (blocks r3 ring gear)
C : Brake (blocks c1 carrier gear)
D : Clutch (couples c3 carrier gear with r4 ring gear)
E : Clutch (couples c1 carrier gear with r2 ring gear)
F : Clutch (couples s1 sun gear with c1 carrier gear)

AMG SpeedShift

AMG SpeedShift TCT

The TCT transmission is essentially the 9G-Tronic automatic transmission including "Torque Converter Technology".

AMG SpeedShift MCT

Mercedes-AMG developed the 9-speed MCT "Multi Clutch Technology" planetary automatic transmission.

The MCT transmission is essentially the 9G-Tronic automatic transmission without a torque converter. Instead of a torque converter, it uses a compact wet startup clutch to launch the car from a stop and also supports computer-controlled double-clutching. The MCT (Multi-Clutch Technology) acronym refers to a planetary (automatic) transmission's multiple clutches and bands for each gear.

The MCT is fitted with four drive modes: “C” (Comfort), “S” (Sport), “S+” (Sport plus) and “M” (Manual) and boasts 100 millisecond shifts in "M" and "S+" modes. MCT-equipped cars are also fitted with the new AMG DRIVE UNIT with an innovative Race Start function. The AMG DRIVE UNIT is the central control unit for the AMG SPEEDSHIFT MCT 9-speed sports transmission and all driving dynamics functions. The driver can change gears either using the selector lever or by nudging the steering-wheel shift paddles. The new Race start Function is a launch control system that enables the driver to call on maximum acceleration while ensuring optimum traction of the driven wheels.

It is available on the 2022 Mercedes-AMG SL-Class (R232)

The new GLC 63 4MATIC+ and GLC 63 S 4MATIC+ feature the AMG SPEEDSHIFT MCT 9-speed transmission, which made its debut in the Mercedes-AMG E 63 4MATIC+. The driver benefits from extremely short shift/response times. Fast multiple downshifts and the double-declutching function make for a highly emotive gearshift experience. A start-off wet clutch replaces the torque converter. This saves weight and optimises the response to the driver's accelerator pedal input, particularly during acceleration and load changes.

Applications

Mercedes models

Mercedes C-Class

• 2015–2021 Mercedes-Benz W205 (all models)
• 2022– Mercedes-Benz W206

Mercedes E-Class

• 2014–2016 Mercedes-Benz W212 (E 350 BlueTec only) available as an option to others.
• 2016–today Mercedes-Benz W213 (all models)

Mercedes S-Class

• 2017–2021 Mercedes-Benz W222 (all except V12 models)
• 2021– Mercedes-Benz W223

Mercedes V-Class

• 2020–present V-Class (W447) (longitudinal engines)

Mercedes GLC-Class

• 2015–present GLC

Mercedes-Benz GLE-Class

• 2016–2019 GLE (W166) (except 63 AMG & 350 models)
• 2020–present GLE (W167) (except 63 models)

Mercedes-Benz GLS-Class

• 2017–2019 GLS (X166) (all except AMG)
• 2020–present GLS (X167)

Non Mercedes-Benz models

Manufactured by JATCO, Ltd as the JR913E under license from Daimler AG.

Nissan

• 2020– Nissan Titan
• 2020– Nissan Frontier
• 2022– Nissan Armada
• 2023– Nissan Z

Infiniti

• 2022– Infiniti QX80

Aston Martin

• 2021– Aston Martin DBX

See also

• List of Daimler AG transmissions

External links

• Nine-Speed Automatic Transmission 9G-Tronic by Mercedes-Benz
• Nomographs and Feasibility Graphs for Enumeration of Ravigneaux-Type Automatic Transmissions