Dodge Ram 47RE and 48RE Transmission Survival Upgrades

Описание: Our 2005 Ram Cummins 3500 4x4 pickup was the last new vehicle we purchased. When we decided to keep vehicles as long as possible, upgrades made sense. Factory equipped with the 48RE automatic transmission, the Ram's powertrain had room for improvements.

Clearly, the 1990-2007 band-type automatic overdrive transmissions behind Cummins engines do have a reliability issue. The original 3-speed A727 was virtually indestructible. The A518/46RE, 47RE and the 48RE tack an overdrive unit onto an A727. For many owners, these transmissions have created headaches like roadside assistance, tow bills and rebuilding costs. At 185,000 miles on the original unit, not yet for us. There are a number of reasons for this success story.

My professional experience with automatic transmissions began with a 1969 diploma at "Automatic Transmission Specialist". Chrysler iron and aluminum case TorqueFlite and Torqueflite transmissions have been familiar since that time. Knowing the 48RE maintenance needs, including periodic band adjustment checks and fluid/filter changes, I also understand the transmission's architecture and weak links.

Before the truck reached 100,000 miles, I was diving into the Sonnax treasure trove of upgrades for stock Chrysler RWD transmissions. At the magazine, a popular article covers each of those Sonnax upgrades that have helped keep this otherwise stock RE transmission reliable. In addition to these upgrades, a roster of BD Diesel survival parts have contributed to the transmission's longevity. You'll learn more in this video.

For model year 2005 only, Chrysler eliminated the driver's ability to lock the 48RE out of overdrive on demand. A BD Diesel overdrive lockout device solved that critical issue. Thanks to the upgrades from Sonnax, the BD Diesel upgrades shared in this video and the ability to lock the transmission in direct 3rd gear on grades, our 48RE should see another 30-50,000 miles before landing on my workbench for a teardown and out-of-chassis, thorough rebuild with a number of internal upgrades.

Despite the bad rap on OEM 47RE and 48RE transmissions, the 48RE has improved planetary gear sets. Recently, the 48RE has become the preferred platform for puller truck competition. Yes, the 68RFE, touted as a huge improvement over the 48RE, is actually less desirable within the racing community.

Part of the reason is the lengthy list of upgrades available for the 48RE. There are billet shafts, explosion proof clutch baskets and more. Not a surprise, really. Once past the overdrive assembly, the 48RE is akin to the A727 Torqueflite that survived in 426 Hemi muscle cars and Class A motorhomes.

The survival of any automatic transmission is dependent on the driver's awareness and sensitivity to loads placed on the transmission. My driving is all about protecting the transmission, especially with a trailer in tow and upshifting with a load. Useful upgrades help prevent premature failure, and routine maintenance is always essential.

As for stamina, if we were buying a new Ram Cummins H.O. with 1075 lb-ft torque, the only automatic available is the Aisin, which is much better than the 68RFE. The G56 manual transmission is long gone as an alternative. Were a strong enough manual transmission available with a factory South Bend clutch, I would opt for the manual transmission.

For more information and how-to visit https://www.4WDmechanix.com and https://forums.4WDmechanix.com.