January 17, 2020

RFE Transmission Universal Valve Bodies: One SKU Does it All!

Henry Ford famously said about the Model T, “You can have any color you want, Sonnax RFE Transmission Remanufactured Valve Body CHR146so long as it’s black.” While this pertained to the cosmetics of the car, it does illustrate the point that uniformity eases production, inventory and forecasting. Imagine what a difference a universal ATF could have in your shop or the impact to your tool budget if a single scanner worked for all transmissions. The cost and time savings would be enormous!

While Sonnax hasn’t invented anything quite that revolutionary, we have lessened the complexity and redundancy of the popular Chrysler 45/545/65/66/68RFE valve bodies by creating a universal RFE remanufactured valve body that works in any early, late, 5- or 6-speed application. So whether your customer is the vehicle owner or the transmission shop, the value of carrying only one valve body to suit all applications is significant.

Channel Casting: Sonnax Resurfaced vs. OE
RFE Transmission Channel Casting: Sonnax Resurfaced vs. Typical OE​​​​​​​

Uniquely designed to fit all ’99-later listed Chrysler applications, regardless of OE checkball or solenoid configuration, this Sonnax remanufactured valve body fixes chronic channel casting warpage, without the added expense of a billet plate.

  • Seasoned channel casting — resurfaced to SAE recommended flatness & surface finish — eliminates warpage, burrs & cross-leaks
  • New, double-thick separator plate & gaskets provide the critical seal between cast surfaces
  • Patented Sonnax accumulator cover plate is stronger than OE to prevent flexing & breaking
  • Patented Sonnax valves & heavy-duty pistons restore hydraulic integrity of circuits to eliminate shift complaints & clutch distress
  • Tested on state-of-the-art equipment to verify that pressures match OE specification

Solenoid Block Connector ColorCheckball Quantity5-Speed6-Speed


Sonnax CHR146White7Yes
Sonnax CHR145Any (Solenoid Not Included)7Yes

As the above chart shows, Chrysler has gone through numerous design iterations on this RFE valve body that results in five to nine different variants depending upon your desire to repair/replace it with a functional or an exact design match.

In 2004, Chrysler significantly changed the original solenoid block (black connector) design to reduce operational noise by switching to internal solenoids (white connector). This was a welcome functional change that also retrofitted back to early designs. In 2010, Chrysler changed the solenoid block (grey connector) again to accommodate a change made to the shifter assembly that no longer offered a Manual 2 or Manual 1 gear shift position. This change provided an “M” manual shift position on the shifter, which allows manual toggle shifting. This shifter change is what led to simplifying the hydraulics associated with the overdrive clutch. In this latest design block, the overdrive solenoid was eliminated, and the multi-function solenoid now is used solely to apply the overdrive clutch. This circuitry change also resulted in the elimination of two checkballs and changes to the separator plate. While the white connector solenoid could still be used in these later design valve body applications, the grey connector block and late valve body could not retrofit to previous applications.

The Sonnax universal RFE remanufactured valve body eliminates the interchange dilemma and inventorying of various part numbers — which, in itself, has huge value. This unique solution contains a host of component improvements, providing a quality solution at reasonable cost. The included heavy-duty, billet aluminum pistons have two guide seal rings to prevent bore scuffing and a mid-piston seal that runs in an unworn portion of the casting bore. Each valve body also includes our patented oversized solenoid switch valve and plugs. These eliminate the chronic wear that causes numerous codes, shift complaints, clutch distress and converter issues, plus prevent the small plugs from sticking. Even the late-design, anodized OE castings are prone to wear at this active switch valve, and the design of the plugs still allows them to cock and jam in the bore. And as only 20% of the nearly 4 million RFE transmissions in the U.S. are being used in Ram 2500/3500 applications (which are the most prone to chipping-related, high-torque, high pressure casting issues), the Sonnax separator plate, gasket and resurfacing approach is a great fix at an affordable price.

Consider stocking either CHR145 or CHR146 to be ready for your next RFE job — whatever the vintage — and benefit from having the exact right valve body, full of valuable Sonnax updates, immediately available.

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While Sonnax makes every effort to ensure the accuracy of technical articles at time of publication, we assume no liability for inaccuracies or for information which may become outdated or obsolete over time.