Mercedes-Benz 9G-Tronic transmission explained

9G-Tronic
Production:	2013–present
Manufacturer:	Daimler AG Jatco Ltd
Class:	9-speed longitudinal automatic transmission
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 N⋅m Eingangsdrehmoment; converter-9-gear-automatic with 700 N⋅m 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.^[1] Initially it debuted on the E 350 BlueTEC in 2013,^{[2] [3]} before launching in the Mercedes-Benz S-Class (W222). It has been expanded to be used in the Mercedes-Benz C-Class (W205) plus the sedan and wagon variants of the Mercedes-Benz E-Class (W213). This transmission was later introduced in the 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.

Development, production and licensing to Jatco Ltd

Development took place at the group's headquarters in Stuttgart-Untertuerkheim. Initially, the transmission was produced only at the Daimler plant not far away in Stuttgart-Hedelfingen. Since April 2016, the transmission has also been produced at Daimler's subsidiary Star Assembly in Sebeș, Romania.^[4] In 2019, the Jatco Ltd, based in Fuji, Shizuoka, Japan, started licensed production for use in Nissan and Infiniti vehicles.^{[5] [6]} In this version, input torque is limited to 700 Nm, allowing each of the gearsets 1, 2, and 4 to use only three planetary gears.^[7] Slightly modified gear dimensions give it a spread of about 9.09.

Specifications

Layout

Progress is reflected in 9 forward gears using 10 main components, compared to 7 forward gears with 11 main components of the direct predecessor. It is fully electronic controlled. Torque converter lock-up can operate in all 9 forward gears. By the end of 2023 unsurpassed ratio span among longitudinal automatic transmissions for passenger cars.

With Assessment!rowspan=2

Weight	Planetary Gearset: Teeth				Count	Total	Avg.
Simpson		Simple
Model Type	Max. Input Torque First Delivery		with Con- verter + Oil	S1 R1	S2 R2	S3 R3	S4 R4	Brakes Clutches	Ratio Span	Gear Step
Gear Ratio	R {i _{R}}	1 {i _{1}}	2 {i _{2}}	3 {i _{3}}	4 {i _{4}}	5 {i _{5}}	6 {i _{6}}	7 {i _{7}}	8 {i _{8}}	9 {i _{9}}
Step	- \tfrac{i _{R}} {i _{1}}	\tfrac{i _{1}} {i _{1}}	\tfrac{i _{1}} {i _{2}}	\tfrac{i _{2}} {i _{3}}	\tfrac{i _{3}} {i _{4}}	\tfrac{i _{4}} {i _{5}}	\tfrac{i _{5}} {i _{6}}	\tfrac{i _{6}} {i _{7}}	\tfrac{i _{7}} {i _{8}}	\tfrac{i _{8}} {i _{9}}
Step 2			\tfrac{i _{1}} {i _{2}} : \tfrac{i _{2}} {i _{3}}	\tfrac{i _{2}} {i _{3}} : \tfrac{i _{3}} {i _{4}}	\tfrac{i _{3}} {i _{4}} : \tfrac{i _{4}} {i _{5}}	\tfrac{i _{4}} {i _{5}} : \tfrac{i _{5}} {i _{6}}	\tfrac{i _{5}} {i _{6}} : \tfrac{i _{6}} {i _{7}}	\tfrac{i _{6}} {i _{7}} : \tfrac{i _{7}} {i _{8}}	\tfrac{i _{7}} {i _{8}} : \tfrac{i _{8}} {i _{9}}
Shaft Speed	\tfrac{i _{1}} {i _{R}}	\tfrac{i _{1}} {i _{1}}	\tfrac{i _{1}} {i _{2}}	\tfrac{i _{1}} {i _{3}}	\tfrac{i _{1}} {i _{4}}	\tfrac{i _{1}} {i _{5}}	\tfrac{i _{1}} {i _{6}}	\tfrac{i _{1}} {i _{7}}	\tfrac{i _{1}} {i _{8}}	\tfrac{i _{1}} {i _{9}}
Δ Shaft Speed	0 - \tfrac{i _{1}} {i _{R}}	\tfrac{i _{1}} {i _{1}} - 0	\tfrac{i _{1}} {i _{2}} - \tfrac{i _{1}} {i _{1}}	\tfrac{i _{1}} {i _{3}} - \tfrac{i _{1}} {i _{2}}	\tfrac{i _{1}} {i _{4}} - \tfrac{i _{1}} {i _{3}}	\tfrac{i _{1}} {i _{5}} - \tfrac{i _{1}} {i _{4}}	\tfrac{i _{1}} {i _{6}} - \tfrac{i _{1}} {i _{5}}	\tfrac{i _{1}} {i _{7}} - \tfrac{i _{1}} {i _{6}}	\tfrac{i _{1}} {i _{8}} - \tfrac{i _{1}} {i _{7}}	\tfrac{i _{1}} {i _{9}} - \tfrac{i _{1}} {i _{8}}
W9A ALL 725.0	1000Nm 2013		95kg (209lb)^[8]	46 98	44 100	36 84	34 86	3 3
Gear Ratio		\tfrac{ 6 , 835 }{ 1 , 242 }	\tfrac{ 10 }{ 3 }	\tfrac{ 125 }{ 54 }		\tfrac{ 1 , 075 }{ 888 }		\tfrac{ 58 , 781 }{ 67 , 944 }	\tfrac{ 43 }{ 60 }	\tfrac{ 52 , 675 }{ 87 , 576 }
Step		1.0000	1.6510	1.4400		1.3722	1.2106		1.2072	1.1915
Step 2			1.1465	1.0333		1.1335	1.0473		1.0131
Speed	–1.1159	1.0000	1.6510	2.3774	3.3130	4.5459			7.6789	9.1495
Δ Speed	1.1159	1.0000	0.6510	0.7264	0.9356	1.2329			1.3178	1.4706
W9A ALL 725.0	1000Nm 2016		95abbr=onNaNabbr=on	46 98	44 100	37 83	34 86	3 3
Gear Ratio		\tfrac{ 13 , 670 }{ 2 , 553 }	\tfrac{ 120 }{ 37 }	\tfrac{ 250 }{ 111 }		\tfrac{ 1 , 075 }{ 888 }			\tfrac{ 43 }{ 60 }	\tfrac{ 52 , 675 }{ 87 , 576 }
Step		1.0000	1.6510	1.4400		1.3511	1.2106		1.2072	1.1915
Step 2			1.1465	1.0457		1.1160	1.0473		1.0131
Speed	–1.1159	1.0000	1.6510	2.3774	3.2737	4.4231			7.4714	8.9022
Δ Speed	1.1159	1.0000	0.6510	0.7264	0.8964	1.1493			1.2822	1.4308
Jatco 9AT JR913E	700Nm 2019		99.5kg (219.4lb)^[9]	45 96	41 91	38 86	37 92	3 3
Gear Ratio		\tfrac{ 51 , 026 }{ 9 , 405 }	\tfrac{ 62 }{ 19 }	\tfrac{ 2 , 821 }{ 1 , 254 }		\tfrac{ 8 , 372 }{ 6 , 855 }			\tfrac{ 92 }{ 129 }	\tfrac{ 66 , 976 }{ 112 , 227 }
Step		1.0000	1.6626	1.4505		1.3503	1.2213		1.2085	1.1950
Step 2			1.1462	1.0634		1.1056	1.0526		1.0113
Speed	–1.1305	1.0000	1.6626	2.4117	3.2899	4.4423			7.6074	9.0910
Δ Speed	1.1305	1.0000	0.6626	0.7491	0.8782	1.1525			1.3124	1.4836
Ratio R & even	i _{R} = - \tfrac{R _{1} R _{2} (S _{3} + R _{3)}} {S _{1} (S _{2+R} _{2)} S _{3}}		i _{2} = \tfrac{S _{3+} R _{3}} {S _{3}}		\tfrac{S _{3} (S _{4+} R _{4)+} R _{3} S _{4}} {S _{3} (S _{4+} R _{4)}}		i _{6} = \tfrac{ 1 } { 1 }	i _{8} = \tfrac{R _{4}} {S _{4+} R _{4}}
Ratio odd	\tfrac{(S _{1} (S _{2+} R _{2)+} R _{1} S _{2)} (S _{3+} R _{3)}} {S _{1} (S _{2+} R _{2)} S _{3}}		i _{3} = \tfrac{R _{2} (S _{3+} R _{3)}} {(S _{2+} R _{2)} S _{3}}		i _{5} = \tfrac{R _{2} R _{4}} {R _{2} R _{4-} S _{2} S _{4}}		\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)}}		\tfrac{R _{1} R _{2} R _{4}} {S _{1} S _{4} (S _{2+} R _{2)+} R _{1} R _{2} (S _{4+} R _{4)}}
Algebra And Actuated Shift Elements
Brake A	❶								❶	❶
Brake B	❶	❶		❶	(❶)	❶		❶		❶
Brake C	❶	❶	❶	❶	❶
Clutch D			❶	❶		❶	❶
Clutch E		❶	❶				❶	❶	❶
Clutch F					❶	❶	❶	❶	❶	❶

Nomogram

▶️ 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 3^rd 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 3^rd ordinate for the 10 gear ratios.

This nomogram reflects the version from 2013.

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.

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

• 2018–2021 Mercedes-Benz W205 (all models)
• 2022–present Mercedes-Benz W206

Mercedes E-Class

• 2014–2016 Mercedes-Benz W212 (E 350 BlueTec only) available as an option to others.
• 2016–2023 Mercedes-Benz W213
• 2023–present Mercedes-Benz W214

Mercedes S-Class

• 2015–2021 Mercedes-Benz W222 (all except V12 models)
• 2021–present Mercedes-Benz W223

Mercedes V-Class

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

Mercedes GLC-Class

• 2015–2022 GLC (X253)
• 2022–present GLC (X254)

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)

Mercedes-Benz SLK-Class

• 2015–2020 SLC (R172) (except 55 AMG)

Mercedes-AMG models

Mercedes-AMG SL

• 2022–present AMG SL (R232)

Jatco Ltd model JR913E

Nissan

• 2020–2024 Nissan Titan
• 2020–present Nissan Frontier
• 2023–present Nissan Z (RZ34)

Aston Martin

• 2021–present Aston Martin DBX

See also

• List of Daimler AG transmissions
• List of Jatco transmissions

External links

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

Notes and References

1. Web site: 50 Jahre Mercedes-Benz Automatikgetriebe . de . 2011-04-12 . 2015-02-09 . https://web.archive.org/web/20150209214958/http://media.daimler.com/dcmedia/0-921-657490-49-1381889-1-0-0-0-0-1-0-0-0-1-0-0-0-0-0.html . 2015-02-09.
2. Web site: New nine-speed automatic transmission in the Mercedes-Benz E 350 BlueTEC: Premiere of the new 9G-TRONIC – Daimler Global Media Site . Media.daimler.com . 2020-01-16.
3. Web site: Mercedes-Benz E350 BlueTec gains nine-speed automatic transmission. 22 July 2013.
4. Web site: Daimler starts production of nine-speed automatic transmissions in Romania. evertiq.com. April 7, 2016. October 21, 2023.
5. Web site: Daimler-Renault-Nissan – The alliance in action.
6. Web site: Fact Sheet:Press Releases and Project Overview Daimler & Renault-Nissan Alliance.
7. Web site: Jatco Technical Review No. 20 - 2021 - see cutaway model Figure 4 - page 72 . November 2022.
8. Web site: 9G-Tronic · Vertiefende Informationen . 2015-11-20. https://web.archive.org/web/20151120173720/http://m.mercedes-benz.de/de_DE/9g-tronic/detail.html. 2015-11-20.
9. Web site: Jatco Technical Review No. 20 · 2021 · see Table 1 · Page 72 . 2022-11-11.