The 47RE is the later, stronger, electronically controlled successor to the 46RE, designed for heavy-duty use and diesel applications, with upgraded internals and electronics. The 46RE is the earlier four-speed automatic that uses older electronic controls and lighter-duty components.
Overview of the 46RE and 47RE
Both the 46RE and 47RE are four-speed automatic transmissions produced by Chrysler for rear-wheel-drive Dodge Ram trucks in the late 1990s and early 2000s. The “RE” designation indicates electronic control of the transmission. The 46RE appeared first and was used with gasoline engines, while the 47RE followed as a more robust, diesel-focused evolution intended to handle higher torque and tougher duty cycles.
Key technical differences
Below is a high-level comparison of the main hardware and control differences you’re likely to encounter:
- Torque capacity and gearing: The 47RE is designed to handle higher torque and often features a stronger internal gearing and clutches compared with the 46RE.
- Internal components: The 47RE typically uses upgraded input shafts, planetary gears, and clutch packs to improve durability under heavy loads.
- Valve body and controls: The 47RE incorporates updated hydraulic and electronic controls, with shift logic and lock-up strategies refined for more demanding use (including diesel applications).
- Electronic control: Both rely on electronic control, but the 47RE generally uses newer software calibrations and PCM/TCM integration for more precise shifting and torque-converter control.
- Application and fit: The 46RE is commonly found in Ram trucks with gasoline engines from the era, while the 47RE is more commonly paired with Cummins diesel engines and heavy-duty configurations; while they share a family design, direct interchange isn’t guaranteed without supporting hardware changes.
Concluding: The 47RE represents an evolutionary upgrade over the 46RE, offering increased durability and refined electronic control for higher-load applications. If you’re swapping or rebuilding, verify compatibility beyond the basic transmission shape.
Applications and compatibility
Understanding which engine and year range each transmission served helps when sourcing parts or planning an upgrade:
- 46RE usage: Predominantly found in Ram trucks with gasoline V8 engines in the mid-to-late 1990s and early 2000s; used where a four-speed automatic with electronic control was adequate for the duty cycle.
- 47RE usage: More commonly associated with heavy-duty configurations and Cummins turbo-diesel installations in Ram 2500/3500 trucks during the late 1990s to early 2000s; designed for higher torque and sustained duty.
- Interchangeability notes: While the two share a family lineage, direct interchange is not always possible without addressing auxiliary components such as the torque converter, wiring, valve body, engine coupling, and PCM/TCM programming.
Concluding: Correct identification of year, engine pairing, and transmission code is essential when sourcing replacements or performing swaps to avoid compatibility issues.
Maintenance and reliability considerations
Maintenance history and usage patterns influence how these transmissions perform and age:
- Common wear points: Valve bodies, solenoids, bands, and pump/turbine assemblies can develop wear over time in both transmissions; the 47RE generally benefits from the design enhancements for heavy-duty use.
- Parts availability: Aftermarket parts exist for both models, but availability and compatibility can vary by year and engine combination. Verify part numbers and fitment for your exact build.
- Duty cycles and towing: For heavy towing or diesel applications, the 47RE is typically preferred due to its strengthened internals and refined controls, though regular maintenance remains crucial for longevity.
Concluding: Regular oil changes with the correct specification, timely valve-body checks, and attention to torque converter condition are key to longevity for either model. When in doubt, consult a shop experienced with Mopar hydraulic/electronic transmissions.
Practical identification and upgrade tips
These quick guidelines can help you determine what you’re dealing with and plan an upgrade or replacement:
- Check the transmission code tag or build plate to confirm 46RE vs 47RE, along with year and engine pairing.
- If upgrading from gas to diesel use, expect that the 47RE is the more suited option, but be prepared for supporting hardware and electronics changes.
- Verify PCM/TCM compatibility and any required calibration when mixing components or performing non-stock swaps.
Concluding: Accurate identification saves time and money and ensures you source the right parts and software calibrations for your vehicle.
Summary
The 46RE and 47RE are related four-speed, electronically controlled transmissions used in Dodge Ram trucks in the late 1990s and early 2000s. The 47RE is the upgraded, stronger, diesel-oriented successor to the 46RE, featuring reinforced internal components, an updated valve body, and newer electronic controls. For maintenance, repairs, or swaps, confirm year, engine pairing, and transmission code to ensure compatibility, and plan for potential electronics and hardware changes when moving from one model to the other.