The "RFE" stands for Rear-wheel drive Fully Electronic control. The RFE design was mostly noted in the new design to have 3 planetary sets for a 4-speed transmission in the 45RFE.In 2007, Chrysler debuted the new 6.7 Powerplant in the all new Dodge Ram, and Dodge wanted a transmission that was specifically designed for function. The previous platform utilized the Torqueflite 48RE platform and had been around since the late 50's when they released the first 727 in 1956 after purchasing the license from Simpson on the gearset in 1955.
The 46/47/48 Chrysler platforms were 3 and 4-speed units that were mechanically and hydraulically controlled, with the most notable control system being governor pressure.
The first improvement Chrysler wanted to make over the Torqueflite platform was, obviously, the amount of forward gear. For the 68RFE transmission, Chrysler opted to change to a six-speed unit. The additional gears allowed Chrysler to add higher 1st-gear ratios and tighter shift recovery from one gear to the next. The tighter shift recovery essentially keeps the vehicle in higher averaged horsepower and torque numbers, while also adding torque multiplication.
The gear ratios were increased. as well. The new 68RFE boasts a whopping 3.23:1 first gear, compared to the 2.45:1 first gear found in the previous 47/48RE platform. Chrysler also increased second gear to a 1.83:1 versus the 1.45:1 found previously. The 68RFE was also given two overdrive gears, with 5th being .81:1 and 6th with the very deep .62:1. The predecessor had a single overdrive that was a .69:1.
The Category Kits
The SunCoast Category 68RFE transmission rebuild kits are designed and developed with intentions of taking a systematic approach to solving the issues with the 68RFE transmission. We approach each deficiency and need from a scientific approach.
These kits offer you the same recipes that are used in our facility. We aim to offer you the most complete series of 68RFE rebuild kits available on the market today.
The Smart Tech Drum
The factory overdrive clutches are at a high risk of failure when towing or installing aftermarket programmers, delete kits, or larger turbos. This is in large part to the fragile and thin (.034) single-sided clutches. When exposed to increased torque or higher temperatures, they will distort, causing additional clearance and uneven apply. This will always result in burnt clutches. These clutches in the overdrive housing are, by far, the weakest link in the 68RFE transmission design.
The Sonnax Smart Tech 68RFE overdrive drum addresses these issues. The new billet clutch housing holds a physically taller clutch pack, allowing the overdrive apply clutch area to increase 16%. In addition to the increased apply surface area, the thicker clutches and steels increase clutch steel mass by 28%, drastically improving the heat dissipation.
The new 68RFE overdrive clutch drum also comes with a top bolt-on plate to help eliminate clutch pack flexing and distortion that contribute to premature failure.
The 2C Piston
The factory molded piston is prone to uneven apply which leads to excessive heat in the clutches and steels creating premature failure. In this 68RFE transmission rebuild kit we replace the factory piston with a much improved billet piece that also allows for one additional clutch further increasing surface apply area.
These new 68RFE transmission rebuild kits are designed with the builder in mind, we offer from mild to wild depending on what your needs are.Dodge trucks pulling heavy loads or boosted to 400600HP are at high risk for overdrive burnup due to the stock transmissions insufficient clutch capacity and fragile OE clutches. Even small amounts of heat and extra torque will push the thin (.034"), single-sided clutches over the edge, distorting the clutch pack. The fact is, any distortion of the clutch pack takes the clearance out of spec and makes overdrive clutch burnup inevitable. Keep hardworking trucks on the road with the Sonnax Smart-Tech® overdrive clutch housing kit 72960-06K. The unique billet aluminum housing holds a physically taller clutch pack and increases OD apply area by 16%. Plus, 2X thicker clutches increase clutch pack steel mass by 28% for unrivaled heat dissipation. This groundbreaking new kit is the only top-of-the-line upgrade that eliminates clutch problems without relying on valve body/pump modifications or adding the expense of extra components. Modified housing holds physically larger clutch pack for 20% more clutch capacity 2X Thicker steels and double-sided clutches increase steel mass by 28% for unrivaled heat dissipation Bolt-on anchor plate eliminates clutch pack flexing and distortion that contribute to heat build-up 16% More OD apply area for firmer, more controlled shifts Combine with Sonnax line pressure booster kit RFE-LB1 for even higher levels of performance
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