Specification
The 545RFE transmission family is a line of electronically controlled automatic transmissions developed by Chrysler for Dodge, Jeep, and Ram vehicles. Known for their durability, adaptability, and towing capability, RFE transmissions are widely used in light-duty and heavy-duty truck applications.Starting with the 45RFE, Chrysler introduced a robust 4-speed platform that shared hardware with later models but was software-limited. This design allowed seamless evolution into the 545RFE and 65RFE, adding improved shift logic, enhanced torque converter design, and better drivability.
With an approximate 450 lb-ft torque rating, its 545RFE model design has a one-piece die-cast aluminum enclosure with incorporated ribs to provide torsional rigidity and it is the standard powertrain backbone of the Dodge Ram 1500, Jeep Grand Cherokee and Dodge Durango with the 4.7L V8 and 5.7L Hemi engines. It is strong but its adaptive shift logic depends on its Transmission Control Module (TCM) and so correct fluid maintenance with ATF+4 is very crucial to its long life.
Engine Variants
45RFE
This was the same version compared in appearance to the 545RFE but the initial 4-speed release that existed in 1999-2000 Jeeps and Dodges. It has the same hard parts such as gears, solenoids, and the case, and was even software-locked at the factory to prevent the 5th overdrive gear, which is why many owners upgrade or replace it with stronger Chrysler-compatible units like the 47RE transmission, thus, most 45RFE units can be easily hacked by just flashing into a 5-speed 545RFE.
65RFE
Launched in 2012 on the Ram 1500, the 65RFE is basically a 545RFE with updated torque converter internals and new software. This update permits the transmission to engage all six forward gear ratios sequentially, making it a lighter-duty alternative to heavy-duty Ram options such as the 66RFE transmission, including the former skip-shifted “2nd Prime” gear, when in Electronic Range Select (ERS) mode, which essentially enables it to be sold as a 6-speed automatic.
66RFE (Heavy Duty Hybrid)
The 66RFE is a strong hybrid model that comes on Ram 2500 gas trucks that have the 6.4L Hemi. It smartly takes the standard 545RFE casing and gear train, but steals the tougher internals, including the clutches, shafts, and oil pump, of the diesel rated Aisin 68RFE to be able to run much heavier payloads and much heavier towing loads.
Frequently Asked Questions
What is the main difference between 45RFE, 65RFE, and 66RFE?
The 45RFE is a software-limited 4-speed, the 65RFE is a refined 6-speed with improved shift logic, and the 66RFE is a heavy-duty hybrid designed for higher towing loads.
Can a 45RFE be converted into a 545RFE?
Yes. Most 45RFE units share identical hardware with the 545RFE and can be converted through PCM flashing, unlocking the additional overdrive gear.
Is the 66RFE better for towing than the 65RFE?
Yes. The 66RFE uses reinforced internals derived from the diesel-rated 68RFE, making it significantly stronger and better suited for heavy towing and payloads.
What vehicles commonly use RFE transmissions?
RFE transmissions are found in Dodge Ram trucks, Jeep Grand Cherokee models, Dodge Durango, and Ram 1500–2500 platforms depending on the variant.
How long does an RFE transmission typically last?
With proper maintenance, RFE transmissions can last 150,000–250,000 miles, and even longer when fluid changes, cooling upgrades, and towing limits are respected.
545RFE Transmission