Mercedes diesel manual transmission
There has been much controversy regarding lubricant selection, with many owners and industry experts arguing that using ATF+4 to lubricate the transmission, as Chrysler recommends, can cause it to fail prematurely. Mercedes-Benz recommends a thicker 75W or 90W gear oil in their trucks that are equipped with the G56. It is debatable whether anything is gained by switching to a 75W/90W gear oil, but many owners choose to do so. A tooth was removed from the input shaft gear for the 2007.5 model year, resulting in a ratio change for the 6.7L Cummins version. When equipped in 6.7L applications, torque was derated to 610 lb-ft for 2007.5 to 2012 model years, and has been derated to 660 lb-ft for 2013 to current model years. Meanwhile, the Cummins Turbodiesel is available with up to 900 lb-ft equipped with an automatic transmission.
G56 Transmission Ratios
|
Application |
1st |
2nd |
3rd |
4th |
5th |
6th |
|
|
2005 - 2007 MY |
6.29 : 1 |
3.48 : 1 |
2.10 : 1 |
1.38 : 1 |
1.00 : 1 |
0.79 : 1 |
|
|
2007.5 - present MY |
5.94 : 1 |
3.28 : 1 |
1.98 : 1 |
1.31 : 1 |
0.74 : 1 |
5.42 : 1 |
G56 Transmission Specs
|
Transmission: |
Mercedes-Benz G56 |
|
Type: |
|
|
Manufacturer: |
Mercedes-Benz |
|
Predecessor: |
New Venture NV5600 |
|
Model Years/Applications: |
2005 - present Ram 2500/3500 w/ Cummins Turbodiesel |
|
Synchronized: |
Synchronized in all forward gears and reverse |
|
Case Material: |
Aluminum |
|
Max Input Torque: |
N/A, suggested under 700 lb-ft |
|
Weight: |
~ 200 to 225 lbs |
|
Fluid Capacity: |
~ 4.95 quarts (9.9 pints) |
|
Fluid Type/Spec: |
SAE 75W/90W gear oil (recommended by Mercedes-Benz), ATF+4 automatic transmission fluid (recommended by Ram Trucks) |
|
Service Intervals: |
Replace transmission fluid every 60, 000 miles |
|
Features: |
• Designed specifically for light and medium duty diesel truck applications • Manufactured in Brazil |
Both the NV5600 and G56 manual transmissions were available