5G-Tronic is
Mercedes-Benz's
trademark name for its five-speed
automatic transmission, starting off with the W5A 580 and W5A 330 (Wandler-5-Gang-Automatik bis 580 oder 330 Nm Eingangsdrehmoment; converter-5-gear-automatic with 330
N⋅m (243
lb⋅ft) or 580
N⋅m (428
lb⋅ft) maximum input torque; type 722.6) as core models.
Abstract
The 5G-Tronic (model W5A 330 and W5A 580 · type 722.6) is an electronically shifted 5-speed overdrive
automatic transmission with
torque converter lock-up (typically in gears 3, 4 and 5) and 2-speed for reverse. In all applications this transmission is identified as the New Automatic Gearbox Generation One, or NAG1.
It replaced the older 4-speed
4G-Tronic transmission-family and its 5-speed derivative, and was replaced by the much more complex and costly 7-speed[a] Mercedes-Benz
7G-Tronic (model W7A 700 · type 722.9) transmission with 11 main components introduced in 2003. Due to its high torque capacity (up to 1,000
N⋅m (738
lb⋅ft)) and lower cost, it was retained for turbocharged V12 engines, four-cylinder applications and commercial vehicles for almost a decade. It is still being built for niche applications (e.g. Sprinter with petrol/CNG M111 engine, Jeep Wrangler, etc.).
Specifications
Layout
Progress is reflected in 5 forward gears[b] using 9 main components, compared to 5 forward gears[c] with 11 main components in the
direct predecessor. It is fully electronically controlled and equipped with a torque converter lock-up.
^Layout • Input and output are on opposite sides • Planetary gearset 1 is on the input (turbine) side • Input shafts are R1 and, if actuated, R2 • Output shaft is C2 (planetary gear carrier of gearset 3)
^
abcdefghijklmnoStandard 50/50: 50/50 are above/below average step With consistently falling gear steps (row highlighted in yellow), the lower half of them (rounded down, here the first two) is always larger and the upper half of them (rounded up, here the last two) is always smaller than the average gear step (cell highlighted in yellow two rows above). Deviating gear steps (red bold) indicate an unfavorable gearset selection
^
abcdefghijklmStandard REV: reverse gear is similar to 1st gear Reverse and 1st gear should have the same ratio. Plus 11 % minus 10 % compared to 1st gear is good, plus 25 % minus 20 % is acceptable (red); even larger deviations (bold) can impair the driving experience, especially when towing a trailer. A torque converter can only partially compensate for this deficiency
^Standard FIRST: gear step 1st to 2nd gear With consistently falling gear steps, the largest gear step is the one from the 1st to the 2nd gear, although it should be limited for a smooth gear shift. A ratio step of up to 5 : 3 (1.6667 : 1) is good, up to 7 : 4 (1.7500 : 1) is acceptable (red); above (bold) is unsatisfactory
^
abcdefghijklmnopqrstuvwxStandard SECOND: 2nd degree steps above 1 With consistently rising (from right to left) gear steps, each 2nd degree step (first row highlighted in green) is larger than 1. Smaller than its predecessor is acceptable (red); smaller than 1 (bold) is unsatisfactory
^
abcdefghijklStandard SPEED: shaft speed difference increase One difference that runs counter to the consistent increase in shaft speed differences (second row highlighted in green) is acceptable (red); two consecutive ones (bold) indicate an unfavorable gearset selection
Activated by a toggle switch, Winter mode sets the gearbox to start off in 2nd gear, both in Drive and Reverse. This is designed to reduce wheelspin on icy surfaces. Also in "W" mode the transmission will shift at lower speeds. "S" mode is not sport but Sommer (German for summer) or Standard.
With Jaguar XJR applications the switch is labelled "Sport". In regular driving mode the gearbox starts off in 2nd gear, both in Drive and Reverse, and will only engage 1st gear when triggered via the kickdown switch (Drive only). While "Sport" mode is enabled the gearbox will always start off in 1st gear.
Speedshift (2001–)
Speedshift is a performance feature set for the Mercedes-Benz transmissions which includes manual mode and active downshifting. When cornering at high speed, the transmission maintains the same gear above a certain lateral acceleration level. It can also automatically downshift before overtaking.
It was first used in 2001 Mercedes-Benz C 32 AMG[3] and 2001 Mercedes-Benz SLK 32 AMG.[4]
AMG Speedshift (2002–)
A version with mechanical lock-up of the torque converter from first gear and steering-wheel-mounted shifter. AMG Speedshift is also used in 7G-Tronic transmission.[5]
It was first used in 2002 Mercedes-Benz E 55 AMG, S 55 AMG, C55, CL 55 AMG.[6]