The Chrysler 545RFE is One Hell Of A Tough Transmission And Here’s Why
Posted by Regis on Wednesday, January 2nd, 2013
The Chrysler 545RFE is a four speed automatic made by the Chrysler Corporation. The “RFE” at the end of the name of the transmission refers to Rear-wheel drive and Full Electronically controlled. The 545RFE first went into production in 1999 Jeep Grand Cherokee’s. Over the years it was used in the Jeep Liberty and Wrangler, Dodge Ram, Power Wagon, Dakota and Durango. It is still in production, mainly in the London Taxi Company TX4.
The transmission is produced at the Chrysler transmission factory in Kokomo, Indiana. This transmission is especially tough in that it includes a three planetary gear set instead of the two planetary gear set typically found in other four speed automatics. Other features of this transmission include three multiple-disk input clutches as well as three multiple-disc holding clutches. It also includes a unique dual filtration system, with one filter in the transmission pan and a second one in the fluid return system. The transmission features a very step 3.00:1 first gear ratio, making it ideal for towing and use in heavy vehicles. It also includes a very generous overdrive ratio of 0.67:1 which helps these work-horse vehicles return the best mileage possible.
Depending on the year of the transmission, it is controlled by a stand-alone computer or controlled by the main computer controlling the rest of the systems in the vehicle. The stand-alone versions are ideal for transplant into vehicles that did not originally come equipped with this transmission. Ideal uses could range from off-road vehicles, to muscle cars, to high horse power street rods and drag racing cars.
Maintenance is crucial to the longevity of the transmission. It is highly recommended that the fluid be changed every 25,000 miles or sooner, especially if used for towing. The transmission uses Mopar ATF +4 fluid and requires 6 – 8 quarts of fluid when draining just the pan. It is also recommended that both transmission filters be changed at the time of the fluid service. It is also recommended that an aftermarket transmission cooler be install if the vehicle will see heavy towing or heavy payloads. The ideal place to mount the transmission cooler is In between the transmission line coming out of the factory cooler and the line going back into the transmission (return line).
Popular upgrades to the 545RFE transmission include reprogramming the transmission with a hand held tuners, installation of a shift improvement kit, installation of a transmission temperature gauge and the use of a deeper than stock transmission pan. If given a choice in choosing the type of material the pan is made of, choose aluminum. Aluminum pans are more ridged than steel pans and help strengthen the transmission case. Aluminum pans also provide an additional cooling benefit, as it dissipates heat better than regular steel.
The 545RFE is a tough transmission, as long as the scheduled maintenance is keep up and the transmission is not abuse from overheating or towing beyond the recommend maximum limit. If you are a travel trailer enthusiast, and you are towing a trailer for long distances, you definitely need to make sure your transmission is in top condition. I can’t stress the importance of installing a transmission cooler like the one I spoke about earlier.
Like all other transmissions, the 545RFE is designed to have a finite life span. In the event that your customer’s 545RFE transmission fails, consider replacing it with a re-manufactured transmission instead of one that has simply been rebuilt.