Mercedes Transmission Shifts (5 speed)
StarShift
This MBUSA press release from July 31, 1997 explains the shifts.
All 1998 Mercedes-Benz Models Feature Five-Speed Automatic Transmission
Electronic Transmission is Driver-Adaptive, Responsive and Fuel-Efficient
MONTVALE, N.J. -- All 1998 Mercedes-Benz passenger vehicles sold in North America feature a driver-adaptive five-speed electronic automatic transmission. The electronically-controlled transmission has five forward gears for better fuel economy and acceleration, as well as state-of-the art computer controls for smooth, flexible operation. Most models even have a "winter" mode which features an additional, "higher" (numerically lower) reverse gear ratio, second-gear forward start and lower overall shift points, for maximum stability and traction on snow and ice.
In spite of being a five-speed, the gearbox uses only three planetary gear sets and six shift elements, instead of the usual four gear sets and seven shift elements. It has no conventional brake bands, only multi-plate clutches for both driving and braking the planetary gears. As a result, the Mercedes transmission unit weighs 176 pounds and is only two feet in length.
Smart Shifting
The heart of the fully electronic transmission is a high-performance microprocessor which is designed so the transmission shifts as the driver expects and wishes it to react. Continuous electronic networking with the engine and chassis management systems allows the transmission computer to adapt to a wide variety of driving situations, and even to the driver's style. By comparing road speed changes and "load" or throttle opening, the transmission computer can instantly discern uphill and downhill grades, and adjust shifting as a result. It avoids annoying shifts back and forth between two gears on a long incline, and delays upshifts on descents (for engine braking), as a driver is likely to do with a manual transmission. It even considers data from the cruise control system and engine temperature sensor in the shifting decision. The computer also measures how fast the driver presses and releases the accelerator pedal. If the pedal is pressed relatively quickly, the transmission is more likely to downshift, for instance during sporty, more spirited driving, while upshifts are less likely when the pedal is released quickly. With "normal" gas pedal operation, the transmission shifts according to a basic program aimed toward getting the best fuel mileage.
Safe, Smooth Shifting
The transmission computer is also networked to the ABS and traction control systems (and to yaw and steering sensors on cars equipped with the new ESP system) so that it can recognize cornering and low-traction conditions. Based on this data, the transmission may delay or hasten a gear shift to ensure there's no negative effect on vehicle stability or traction control. Not only does the transmission computer adjust shift characteristics according to engine speed and load (very smooth shifts during leisurely driving, crisper shifting with more spirited driving), but it's even able to reduce engine power for a split second (by retarding ignition timing) to ensure smooth gear changes. This fourth generation of Mercedes automatic transmissions uses a refined, proven hydrodynamic torque converter with a special lock-up clutch inside the converter for maximum fuel efficiency. The lockup clutch engages in third, fourth and fifth gears (not just in top gear, as with many other cars) - but still with slight computer-controlled slippage (60-80 rpm difference), to prevent drivetrain noise and vibration. Designed to last the life of the car, the lock-up clutch is submerged in transmission oil and uses special long-life friction materials.
Fail-Safe Shifting
If the electronic system ever fails, the new transmission is designed to revert to basic hydraulic operation. It stays in the selected gear, with the torque converter lock-up clutch open for maximum torque multiplication. On restarting, it operates in second gear, allowing it to be driven to a Mercedes dealer for service.
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Low range increases torque 2.64 times.
Mercedes-Benz StarShift®
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Added for MY2000+:
Transmission: Touchshift with new control system
The tried-and-tested five-speed automatic transmission featuring electronic control, torque converter lockup clutch and Touchshift is part of the standard equipment package for the six-cylinder and eight-cylinder M-Class models. New features include modified control of the convenient Touchshift function, giving the driver even more options for engaging the gear that best suits the situation in hand. This is how it works: holding the selector lever in the "--" position tells the transmission to keep moving down the ratios until the one that can best slow or accelerate the M-Class is found. When driving downhill, the driver thus has the convenient option of shifting down to obtain the best possible engine braking effect. The same is true when acceleration is required, in that the ratio from which the vehicle derives optimum performance can be selected. Manual downshifts into the "optimum" gear are monitored by the transmission ECU.
With independent wheel suspension, ESP., Brake Assist and the four-wheel Electronic Traction Support 4-ETS all fitted as standard, the Mercedes-Benz M-Class already contains some of the most powerful and state-of-the-art chassis and driveline technology available when it rolls off the assembly line. This set-up forms the basis for what is an extraordinary synthesis in automotive circles: exemplary off-road capability combined with high levels of safety and comfort on a par with those seen in a Mercedes saloon.
Automatic transmission
The electronically controlled five-speed automatic transmission in the V6 and V8 models automatically adapts the shift characteristics to suit the situation in hand and individual driver requirements. When cornering, or when driving uphill or downhill, the transmission ECU automatically alters the shift points and, in so doing, prevents any sudden gear changes. Thanks to an on-going process involving the comparison of information provided by the sensors with stored setpoints the transmission is able to adapt to the situation on the road at lightening speed. In addition to this, the ECU records the movements of the accelerator pedal and, using this data, deduces the driver's acceleration requirements. Meanwhile, the torque converter lockup is activated at low road speeds to reduce fuel consumption. The torque converter lockup clutch works on the basis of computer-controlled continuous slip which decouples the engine from the transmission to such an extent that vibrations no longer occur.
The Mercedes-AMG engineers have also adapted the characteristics of the standard-fitted electronically controlled touch-shift five-speed transmission to the sporty temperament of the AMG models. The result is significantly increased spontaneity, which assists a lithe, sporty driving style.
The modified five-speed automatic transmission is used in all the eight-cylinder Mercedes-AMG models.
Six-speed transmission
The six-speed manual transmission is fitted as standard in the ML 270 CDI. By using high-performance synchromesh incorporating multi-cone synchronisers, Mercedes-Benz engineers have succeeded in reducing shift effort by up to 25 percent compared to the previous five-speed manual transmission. In practice this means light and precise shifts with short shift travel.
Copyright DaimlerChrysler AG
ML320 transmission specs
| W 5A 300 (722.662) | ||
| Transmission capacity: Engine torque | 315 Nm | |
| Maximum speed | in gears 1-4 | 6400 rpm |
| in gear 5 | 6000 rpm | |
| in Kickdown gear | 6400 rpm | |
| Converter diameter | 270 mm | |
| Converter ratio | 1.85:1 | |
| Ratios in: | 1st gear | 3.932:1 |
| 2nd gear | 2.408:1 | |
| 3rd gear | 1.486:1 | |
| 4th gear | 1.000:1 | |
| 5th gear | 0.830:1 | |
| Reverse | -3.100:1 | |
| Reverse in 4low | -1.899:1 | |
| Gross Weight | 76.0 kg | |
| Supplier: | MB Hedelfingen | |
Maximum Speeds
| [ MPH ] | ||||||
| 1. gear | 2. gear | 3. gear | 4. gear | 5. gear | ||
| ML320 | 36 | 56 | 93 | 121 | 118 | |
| ML430 | 40 | 67 | 105 | 131 | 130 | |
| ML55 AMG | 40 | 66 | 105 | 146 | 146 | |
Transmission Shifts
| pedal position | shift [ MPH ] | ||||||||
| 1 => 2 | 2 => 3 | 3 => 4 | 4 => 5 | 5 => 4 | 4 => 3 | 3 => 2 | 2 => 1 | ||
| full throttle | 30 | 56 | 89 | 136 | 123 | 67 | 25 | 11 | |
| kick down | 35 | 61 | 94 | 136 | 127 | 85 | 51 | 21 | |
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Kick-down Press the pedal quick and hard all the way down - engaging the kick-down switch, shown here in grey under the gas pedal. Passing with authority Switch into a lower gear manually before passing and then accelerate - without even the slight gear-shift delay. |
http://www.carsoft.ru/avtorepair/akp.html
| Control - unlike any other. |