G56 Transmission Overview
Manufactured in Brazil by Mercedes-Benz, the G56 transmission is a 6-speed manual transmission that was designed specifically for light and medium duty diesel trucks. Compared to the NV5600 transmission that it replaces, the Ram G56 transmission is considerably lighter, and shifts smoother thanks to a dual mass flywheel. It can also handle considerably more torque, however the maximum torque capacity depends upon the model year and configuration. Trucks fitted with the 6.7L Cummins diesel engine and G56 transmission, will produce less torque than the automatic transmission version.
What Transmission Do I Have?
OE G56 6-speed Manual Transmission Applications
2005 – 2018 Ram 2500
2005 – 2018 Ram 3500
2005 – 2018 Ram 4500
2005 – 2018 Ram 5500
G56 Technical Specs
Case: Aluminum
Torque capacity: under 700 lb-ft (depending on MY)
Weight: 200 – 225 lbs
Fluid capacity: 4.95 qts
Fluid type: ATF+4 or 75W/90W gear oil
G56 Transmission Gear Ratios
*2005-2007 MY | 2007.5-2018 MY
1st = 6.29 | 5.94
2nd = 3.48 | 3.28
3rd = 2.10 | 1.98
4th = 1.38 | 1.31
5th = 1.00 | 1.00
6th = 0.79 | 0.74
R = 6.29 | 5.42
Common G56 Transmission Problems
Not suited for modified engines
The transmission case and gears are known to crack due to flex under heavy loads
Dual mass flywheel can fail
Clutch can fail prematurely
What Transmission Do I Have?
Conclusion: G56 Transmission
The G56 transmission is a lightweight transmission that can handle moderately severe use. However, if the engine output has been increased above the stock level, the G56 has been known to fail prematurely due to the increase torque. There have also been concerns about the type of fluid to use in this gearbox, so take that into consideration when buying one.
