1989-1993 Dodge 5.9L Cummins Torque Converters

Torque converters on the 1989-1993 Ram 5.9L Cummins

The A727 TorqueFlite three-speed backed the Cummins from 1989 into 1991. It has no overdrive and a non-lockup converter, and its converters were loose by design to help the drivetrain last. The trade-off is high cruise RPM and extra heat on the highway. The A518 arrived mid-1991 with a 0.69 overdrive. It shifts 1-2-3 hydraulically, while overdrive and converter lockup are handled by electronic solenoids. Under Chrysler's 1992 naming it became the 46RH.

What fails and why

The A518 was short-lived in Cummins trucks; a tougher unit was needed for the 1994 engine. One well-documented 1993 D250 that reached 620,000 miles went through two remanufactured A518s before a converter failure. It was finally rebuilt with a low-stall non-lockup converter, added clutch plates, a new second-gear band and a billet accumulator piston. On these transmissions, watch for slipping, a flare on the 2-3 shift, converter shudder and overheating fluid. The pattern shows up at mid-to-high mileage and gets worse with towing.

What we carry

This group lists the BD Diesel 1060210X Proforce torque converter, listed for 1989-1993 Cummins trucks. Because the A727 and A518 use different converter setups, read the product page to confirm which transmission it is built for before you order.

Fitment notes

Parts sellers often list the 727, A518 and 46RH together for 1989-1993, but the units differ. Count the gears: no overdrive means A727, an overdrive fourth gear means A518 or 46RH. If you run an exhaust brake on an A518 or 46RH, it needs a lockup controller to manage the converter; the non-lockup A727 does not. Manual trucks with the Getrag G360 five-speed use a clutch, not a converter, so nothing here applies to them.

Frequently asked questions

How do I tell whether my first gen has the A727 or the A518?

Build date and gear count. Trucks from 1989 to early 1991 got the A727 three-speed with no overdrive. From mid-1991 the A518 four-speed overdrive took over, and Chrysler's 1992 naming calls it the 46RH. If your automatic has an overdrive gear, it is the A518 or 46RH.

What signs point to converter or transmission trouble on an A518?

Slipping, a flare on the 2-3 shift, converter shudder and fluid that runs hot. They tend to show up at mid-to-high mileage and get worse with towing. On an A727, high cruise RPM and heat come with the design because it has no overdrive and a loose converter.

Do I need a lockup controller for an exhaust brake?

On an A518 or 46RH, yes: an exhaust brake needs a controller to manage converter lockup. The A727 uses a non-lockup converter, so the issue does not apply there.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.