1989-1993 Dodge 5.9L Cummins Built Transmissions

Complete transmissions for the 1989-1993 RAM 5.9L Cummins

Three transmissions came behind the first-gen Cummins. The Getrag G360 5-speed manual was offered for all of 1989-1993. Automatic trucks from 1989 to mid-1991 got the A727 TorqueFlite 3-speed, and from mid-1991 through 1993 they got the A518 4-speed overdrive, sold as the 46RH from 1992. Buyer's guides steer first-gen shoppers toward 1991.5-1993 trucks because they came with the stock intercooler and overdrive. That overdrive matters on the highway: the A727 has none, so it cruises at high rpm and runs hot.

When a complete unit makes sense

The automatics are the weak link on these trucks. The best-known example is a 1993 D250 that reached 620,000 miles on its original long block. It went through two remanufactured A518s before its converter failed, and it only held up once the transmission was rebuilt with a low-stall non-lockup converter, more clutches, a new second-gear band and a billet accumulator piston. If your A518/46RH is slipping, flaring on the 2-3 shift or shuddering at the converter after high miles and towing, it may be time to stop rebuilding to stock and look at a complete unit.

Manual trucks

On the manual side, the G360's upper input bearing wears out from heat and load when the truck tows, and the stock clutch slips once fuel is added. The standard answer is not another G360. The NV4500 5-speed, used behind the 1994-2005 Ram Cummins, is the common swap, and a second-gen-sourced NV4500 with a South Bend clutch is documented on a 1991.5 W250. Built first gens have also run the G56 and the Allison 1000, but those are custom conversions.

What we carry

This page holds complete automatics. BD Diesel lists its 1030311F 518 transmission for 1991-1993 four-wheel-drive Cummins trucks, which makes it a W250 and W350 part. ATS Diesel Performance offers its 618 Transmission Package, listed for 1990-1993 5.9L Cummins trucks. Either one replaces the whole factory automatic instead of chasing one worn part at a time. Torque converters, valve bodies, coolers and rebuild kits for this truck live in the transmission parts section.

Fitment notes

Don't trust the model year alone. The A518 appeared mid-1991, but sellers list 727, A518 and 46RH together for 1989-1993, and the ATS package's listing starts in 1990, before the A518 did. A 1991 truck can have either automatic, so confirm by gear count and VIN. Match the drivetrain too: the BD unit is a 4WD transmission. If you plan an exhaust brake on a lockup A518/46RH, plan on a converter lockup controller as well; the non-lockup A727 doesn't use one. If your truck left the factory with the A727, call before ordering and we'll talk through what the change involves.

Frequently asked questions

Which complete transmission fits my truck?

Start with what is in it now and whether it's 2WD or 4WD. The BD 518 is listed for 1991-1993 4WD trucks, and the ATS 618 package for 1990-1993 5.9L Cummins trucks. Because the A518 arrived mid-1991, a VIN check settles it. Call the shop with yours and we'll confirm before you order.

Why not just put in a stock remanufactured A518?

Because the stock design is the weak point behind the Cummins. The 620,000-mile 1993 D250 went through two remanufactured A518s before a converter failure, and only a rebuild with more clutches, a new second-gear band and a low-stall converter held up. Diesel Hub notes the A518 was short-lived in Cummins trucks because a more robust unit was needed.

Is there a complete replacement for the G360 manual?

The complete units on this page are automatics. The usual path for a worn G360 is an NV4500 conversion. Keep in mind that a South Bend clutch made for the Getrag is specified for the stock input shaft, so an NV4500-swapped truck needs the NV4500 clutch.

Will an exhaust brake work with a new automatic?

On an A518/46RH, which locks the converter, an exhaust brake needs a controller to manage converter lockup. The A727 is non-lockup, so that piece doesn't apply. Tell us your plans when you order and we'll make sure the transmission and brake work together.

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.