Mercedes-Benz 9G-Tronic transmission


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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.

9G-Tronic

Cutaway model of the transmission with components for hybrid drive

Overview
ManufacturerDaimler AG
Jatco Ltd
Production2013–present
Body and chassis
Class9-speed longitudinal automatic transmission
RelatedZF 8HP · Ford-GM 10-speed
Chronology
Predecessor7G-Tronic

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.

Gear Ratios[a]

Gear

Model

 R 1 2 3 4 5 6 7 8 9 Total
Span 		Span
Center 		Avg.
Step 		Compo-
nents
W9A All · 2013 −4.932 5.503 3.333 2.315 1.661 1.211 1.000 0.865 0.717 0.601 9.150 1.819 1.319 4 Gearsets
3 Brakes
3 Clutches
W9A All · 2016 −4.798 5.354 3.243 2.252 1.636 1.211 1.000 0.865 0.717 0.601 8.902 1.795 1.314
9AT All · 2019 −4.799 5.425 3.263 2.250 1.649 1.221 1.000 0.862 0.713 0.597 9.091 1.799 1.318
  1. ^ Differences in gear ratios have a measurable, direct impact on vehicle dynamics, performance, waste emissions as well as fuel mileage

Development, production and licensing to Jatco Ltd

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Development took place at the group's headquarters in Stuttgart-Untertuerkheim.[2] Initially, the transmission was produced only at the Daimler plant not far away in Stuttgart-Hedelfingen.[1] 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 span of about 9.09:1.

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

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.

Progress is reflected in 9 forward gears[a] using 10 main components, compared to 7 forward gears[b] with 11 main components[c] 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.

  1. ^ plus 1 reverse gear
  2. ^ plus 2 reverse gears
  3. ^ 4 planetary gearsets (of which 2 gearsets are combined as a Ravigneaux compound gearset), 4 brakes, 3 clutches
Gear Ratios
With Assessment Weight Planetary Gearset: Teeth[a] Count Total[b]
Center[c] 		Avg.[d]
Simpson Simple[e]
Model
Type 		Version
First Delivery 		with Con-
verter + Oil 		S1[f]
R1[g] 		S2[h]
R2[i] 		S3[j]
R3[k] 		S4[l]
R4[m] 		Brakes
Clutches 		Ratio
Span 		Gear
Step[n]
Gear
Ratio 		R
  		1
  		2
  		3
  		4
  		5
  		6
  		7
  		8
  		9
 
Step[n]  [o]    [p]              
Δ Step[q][r]              
Shaft
Speed 		                   
Δ Shaft
Speed[s] 		                   
W9A ALL
725.0 		1,000 N⋅m (738 lb⋅ft)
2013[t] 		95 kg (209 lb)[9] 46
98 		44
100 		36
84 		34
86 		3
3 		9.1495
1.8194 		1.3188[n]
Gear
Ratio 		−4.9316[o]
  		5.5032
  		3.3333
  		2.3148
  		1.6611[r]
  		1.2106
  		1.0000[s]
  		0.8651[r][s]
  		0.7167
  		0.6015
 
Step 0.8961[o] 1.0000 1.6510 1.4400 1.3935 1.3722 1.2106 1.1559 1.2072 1.1915
Δ Step[q] 1.1465 1.0333 1.0156[r] 1.1335 1.0473 0.9575[r] 1.0131
Speed -1.1159 1.0000 1.6510 2.3774 3.3130 4.5459 5.5032 6.3611 7.6789 9.1495
Δ Speed 1.1159 1.0000 0.6510 0.7264 0.9356 1.2329 0.9573[s] 0.8579[s] 1.3178 1.4706
W9A ALL
725.0 		1,000 N⋅m (738 lb⋅ft)
2016[u] 		95 kg (209 lb)[9] 46
98 		44
100 		37
83 		34
86 		3
3 		8.9022
1.7946 		1.3143[n]
Gear
Ratio 		−4.7983[o]
  		5.3545
  		3.2432
  		2.2523
  		1.6356[r]
  		1.2106
  		1.0000[s]
  		0.8651[r][s]
  		0.7167
  		0.6015
 
Step 0.8961[o] 1.0000 1.6510 1.4400 1.3770 1.3511 1.2106 1.1559 1.2072 1.1915
Δ Step[q] 1.1465 1.0457 1.0192[r] 1.1160 1.0473 0.9575[r] 1.0131
Speed -1.1159 1.0000 1.6510 2.3774 3.2737 4.4231 5.3545 6.1892 7.4714 8.9022
Δ Speed 1.1159 1.0000 0.6510 0.7264 0.8964 1.1493 0.9314[s] 0.8347[s] 1.2822 1.4308
Jatco 9AT
JR913E 		700 N⋅m (516 lb⋅ft)
2019[v] 		99.5 kg (219 lb)[12] 45
96 		41
91 		38
86 		37
92 		3
3 		9.0910
1.7994 		1.3177[n]
Gear
Ratio 		−4.7991[o]
  		5.4254
  		3.2632
  		2.2496
  		1.6491[r]
  		1.2213
  		1.0000[s]
  		0.8619[r][s]
  		0.7132
  		0.5968
 
Step 0.8846[o] 1.0000 1.6626 1.4505 1.3641 1.3503 1.2213 1.1603 1.2085 1.1950
Δ Step[q] 1.1462 1.0634 1.0102[r] 1.1056 1.0526 0.9601[r] 1.0113
Speed -1.1305 1.0000 1.6626 2.4117 3.2899 4.4423 5.4254 6.2950 7.6074 9.0910
Δ Speed 1.1305 1.0000 0.6626 0.7491 0.8782 1.1525 0.9831[s] 0.8696[s] 1.3124 1.4836
Ratio
R & Even 		     [e]    
Ratio
Odd 		         
Algebra And Actuated Shift Elements[w]
Brake A[x] ❶ ❶ ❶
Brake B[y] ❶ ❶ ❶ (❶)[z] ❶ ❶ ❶
Brake C[aa] ❶ ❶ ❶ ❶ ❶[e]
Clutch D[ab] ❶ ❶ ❶ ❶
Clutch E[ac] ❶ ❶ ❶ ❶ ❶
Clutch F[ad] ❶[e] ❶ ❶ ❶ ❶ ❶
  1. ^ Layout
    • Input and output are on opposite sides
    • Planetary gearset 1 is on the input (turbine) side
    • Input shafts are S1, C4 (planetary gear carrier of gearset 4), and, if actuated, C1 (planetary gear carrier of gearset 1)
    • Output shaft is C3 (planetary gear carrier of gearset 3)
  2. ^ Total Ratio Span (Total Ratio Spread · Total Gear Ratio)
    •  
    • A wider span enables the
      • downspeeding when driving outside the city limits
      • increase the climbing ability
        • when driving over mountain passes or off-road
        • or when towing a trailer
  3. ^ Ratio Span's Center
    •  
    • The center indicates the speed level of the transmission
    • Together with the final drive ratio
    • it gives the shaft speed level of the vehicle
  4. ^ Average Gear Step
    •  
    • With decreasing step width
      • the gears connect better to each other
      • shifting comfort increases
  5. ^ a b c d Except in 4th gear when used in the Simpson configuration
  6. ^ Sun 1: sun gear of gearset 1
  7. ^ Ring 1: ring gear of gearset 1
  8. ^ Sun 2: sun gear of gearset 2
  9. ^ Ring 2: ring gear of gearset 2
  10. ^ Sun 3: sun gear of gearset 3
  11. ^ Ring 3: ring gear of gearset 3
  12. ^ Sun 4: sun gear of gearset 4
  13. ^ Ring 4: ring gear of gearset 4
  14. ^ a b c d e Standard 50:50
    — 50 % Is Above And 50 % Is Below The Average Gear Step —
    • With steadily decreasing gear steps (yellow highlighted line Step)
    • and a particularly large step from 1st to 2nd gear
      • the lower half of the gear steps (between the small gears; rounded down, here the first four) is always larger
      • and the upper half of the gear steps (between the large gears; rounded up, here the last four) is always smaller
    • than the average gear step (cell highlighted yellow two rows above on the far right)
    • lower half: smaller gear steps are a waste of possible ratios (red bold)
    • upper half: larger gear steps are unsatisfactory (red bold)
  15. ^ a b c d e f g Standard R:1
    — Reverse And 1st Gear Have The Same Ratio —
    • The ideal reverse gear has the same transmission ratio as 1st gear
      • no impairment when maneuvering
      • especially when towing a trailer
      • a torque converter can only partially compensate for this deficiency
    • Plus 11.11 % minus 10 % compared to 1st gear is good
    • Plus 25 % minus 20 % is acceptable (red)
    • Above this is unsatisfactory (bold)
  16. ^ Standard 1:2
    — Gear Step 1st To 2nd Gear As Small As Possible —
    • With continuously decreasing gear steps (yellow marked line Step)
    • the largest gear step is the one from 1st to 2nd gear, which
      • for a good speed connection and
      • a smooth gear shift
    • must be as small as possible
      • A gear ratio of up to 1.6667:1 (5:3) is good
      • Up to 1.7500:1 (7:4) is acceptable (red)
      • Above is unsatisfactory (bold)
  17. ^ a b c d From large to small gears (from right to left)
  18. ^ a b c d e f g h i j k l m Standard STEP
    — From Large To Small Gears: Steady And Progressive Increase In Gear Steps —
    • Gear steps should
      • increase: Δ Step (first green highlighted line Δ Step) is always greater than 1
      • As progressive as possible: Δ Step is always greater than the previous step
    • Not progressively increasing is acceptable (red)
    • Not increasing is unsatisfactory (bold)
  19. ^ a b c d e f g h i j k l m Standard SPEED
    — From Small To Large Gears: Steady Increase In Shaft Speed Difference —
    • Shaft speed differences should
      • increase: Δ Shaft Speed (second line marked in green Δ (Shaft) Speed) is always greater than the previous one
    • One difference smaller than the previous one is acceptable (red)
    • Two consecutive ones are a waste of possible ratios (bold)
  20. ^ First version with a gear ratio span wider than 9:1.[8] Discontinued 2016
  21. ^ 2nd version introduced without notice with the Mercedes-Benz E-Class (W213) to reduce the step between gear 4 and 5 below the one of the 7G-Tronic (1.3684:1)[10]
  22. ^ Under license from Daimler[11]
  23. ^ Permanently coupled elements
    • R1 and C2
    • R2, S3, and S4
  24. ^ Blocks C1 (carrier 1)
  25. ^ Blocks S2
  26. ^ Not involved. Only serves to maintain the shift logic: only one shift element is changed for step up or down
  27. ^ Blocks R3
  28. ^ Couples S1 with C1 (carrier 1)
  29. ^ Couples C1 (carrier 1) with R2
  30. ^ Couples C3 (carrier 3) with R4
 
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.

This nomogram reflects the version from 2013.

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)

Mercedes-Benz GLE-Class

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

Mercedes-Benz GLS-Class

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Mercedes-Benz SLK-Class

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