1991–1995 Dodge 5.9L Cummins46RH & 47RH Transmissions

The 46RH/A518 was used behind the early 5.9L Cummins and uses hydraulic governor-controlled shifting with overdrive and a non-lockup torque converter. The 47RH/A618, used for 1994–1995 Cummins applications, retains hydraulic shifting but adds a lockup torque converter and increased capacity for the higher-torque application.

The A518/46RH diesel overdrive transmission was used from 1991–1993, with 1991 being a transition year that should be verified by transmission identification. The A618/47RH was used for 1994–1995 Dodge 5.9L Cummins applications. Earlier 1989–1990 Cummins automatic trucks used the three-speed A727 without overdrive.

Yes, but a 46RH-to-47RH swap is a conversion, not a direct transmission replacement. The 47RH lockup converter requires the correct engine adapter, starter, flexplate/converter arrangement and lockup controls. Depending on the truck, transmission mounting, driveshaft and linkage changes may also be required.

The 47RH uses a hydraulic governor for normal transmission shifting, so it does not require the same electronic governor control used by the later 47RE. However, overdrive and torque-converter lockup require electrical control, which must be properly configured in a conversion application.

Yes. A 46RH/A518 or 47RH can be used to add overdrive to an earlier Cummins truck originally equipped with an A727, but it is not a direct bolt-in transmission swap. Crossmember and mount location, driveshaft length, linkage and overdrive controls must be addressed. A 47RH conversion also requires the correct lockup-compatible engine-side hardware and electrical lockup control.