2004.5-2007 Dodge 5.9L Cummins Built Transmissions

Complete transmissions for the 2004.5-2007 Ram 5.9L Cummins

The 48RE behind this engine is a four-speed automatic rated for 560-570 lb-ft of input torque. The 5.9L Cummins makes 600 lb-ft in 2004.5 trucks and 610 lb-ft from 2005 to 2007, so the transmission starts life short of the engine. Built 48RE packages are sold by horsepower and use level rather than as one-size replacements. A built unit pairs upgraded internals with a stronger converter and valve body, and some builders add a double-deep finned pan for cooling. Manual trucks from mid-2005 on carry the Mercedes G56 six-speed, which came with a dual-mass flywheel.

When it is time for a whole transmission

A stock 48RE can fail between 100,000 and 150,000 miles even when the engine has never been touched. The warning signs are slipping, lost converter lock-up, no overdrive, burnt fluid and shifts that are not right. With added power the end can come all at once: input shafts have snapped at as little as about 500 rear-wheel horsepower. When those symptoms show up, a complete built unit replaces the whole weak link at once instead of one part at a time. On the manual side, the G56 has been reported to crack its bellhousing under excessive torque, which is a whole-transmission problem too.

Built 48RE or performance G56

Most owners replacing an automatic stay with a 48RE and pick the build level by power and use; check each listing for what it is built for. Buy for where the truck is going, not where it is today. The 48RE's rating is already below a stock engine, so any added power should be matched with a built unit, and any power upgrade should use CARB EO-numbered parts, verified per product and model year. Owners of G56 trucks have a performance G56 manual here, titled for 2005.5-2018 trucks.

What we carry

BD Diesel 48RE transmission and converter packages in several build levels, including the Roadmaster package and a 4WD-specific package, all titled for 2005-2007 trucks. ATS Diesel Performance supplies a 48RE transmission package titled for 2003-2007 and the ATS G56 performance manual transmission titled for 2005.5-2018 5.9L and 6.7L trucks.

Fitment notes

The BD packages are titled 2005-2007, so a 2004.5 truck, which is a 2004 model year, should be confirmed by VIN before you order. BD also lists a 4WD-specific package, so know your drivetrain. 2007 is split by engine: trucks built after January 1, 2007 have the 6.7L Cummins and a 68RFE, which is not the transmission these packages replace. For the G56, confirm your truck has one; a 2005 manual truck can have the NV5600 instead. See the rest of our Cummins parts for this engine.

Frequently asked questions

Why buy a built 48RE instead of rebuilding my stock one?

Because the stock design is rated for 560-570 lb-ft and the engine makes 600-610 lb-ft. A stock rebuild restores that same rating. Built packages are sold by horsepower and use level, with upgraded converters and valve bodies, so they are made for what this engine actually puts out.

Does a complete transmission come with a torque converter?

The BD packages on this page are sold as transmission and converter packages. Check each listing, including the ATS package, for exactly what is in the box before you plan the install.

I plan to add power later. What should I buy now?

Buy the transmission for the power you plan to make, not the power you make today. Input shafts in these units have snapped at as little as about 500 rear-wheel horsepower, and the stock rating is already short of a stock engine. Keep any power upgrade to CARB EO-numbered parts, and call us with your plans so we can help match the build level.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.