The 2008 Ram 3500 offered different transmissions depending on the engine. In broad terms, gas models with the 5.7-liter Hemi used a 5-speed automatic, while diesel models with the 6.7-liter Cummins could be equipped with either a 6-speed manual or a 6-speed automatic.
This article details how those options were assigned to engines and configurations for the 2008 Ram 3500, and what buyers or owners should look for when identifying or confirming a transmission in a specific truck.
Transmission options by engine
Gasoline engines (5.7L Hemi)
Gasoline Ram 3500s from that year generally came with a single automatic transmission option, paired to the 5.7-liter Hemi engine.
- 5-speed automatic transmission
Gasoline models with the 5.7L Hemi predominantly used the 5-speed automatic, and manual transmissions were not commonly offered with the gas engine in the 2008 Ram 3500 lineup.
Diesel engines (6.7L Cummins)
Diesel-equipped Ram 3500s provided more than one transmission choice, reflecting the heavy-duty nature of the Cummins engine and the needs of buyers who wanted different shift characteristics.
- 6-speed manual transmission
- 6-speed automatic transmission
For the 6.7L Cummins turbodiesel, buyers could select between a 6-speed manual and a 6-speed automatic, depending on the trim, cab/bed configuration, and other options. The manual option was common on many 2008 Cummins models, while the automatic was also available on several configurations.
Notes on variations
Transmission availability can vary by cab/bed configuration, 2WD vs 4WD drivetrain, and market or fleet specifications. If you’re evaluating a specific truck, verify the exact transmission stated on the build sheet or by checking the VIN and its documented options, since individual trucks may have a different pairing based on original order.
Summary
In summary, the 2008 Ram 3500 offered a gas option with a 5-speed automatic behind the 5.7L Hemi, and a Cummins diesel option with either a 6-speed manual or a 6-speed automatic. The precise transmission depended on the engine and the truck’s configured options, so checking the specific vehicle’s documentation is the best way to confirm.