1989-1993 Dodge 5.9L Cummins Towing Parts

Towing with the 1989-1993 RAM 5.9L Cummins

Dodge offered the Cummins in its D250, D350, W250 and W350 pickups and in pickup-based chassis-cab trucks above 8,500 lb GVWR. At launch the 5.9L made 400 lb-ft at 1,600 rpm, against 246 lb-ft from GM's LF9 and 345 lb-ft from Ford's IDI, and that torque is why buyers picked it to pull. Mid-1991 brought three changes that matter when you hook up a trailer: an air-to-air intercooler, the A518 four-speed overdrive automatic, and one-ton frames under the 250 Cummins trucks. Tow-spec trucks were documented with factory overload leaf springs and an external auxiliary transmission cooler with a fan. One survivor D250 hauled hot-shot loads for 101,000 miles in 11 months with that cooler in place. For engine parts beyond the hitch, start at our Cummins hub.

What fails and why

When a first-gen works hard, the documented failures come from heat.

• Getrag G360 5-speed manual. Towing heat kills the input bearing. The warning sign is transmission whine after long tows.
• A518 automatic. It overheats under towing. Slipping or burnt fluid after a long pull points there.
• Non-intercooled trucks. Trucks built from 1989 to mid-1991 without the intercooler run higher exhaust gas temperature when towing, and EGT creeps up on grades. The factory intercooler significantly improves cooling and towing capability. The change came mid-year, so check for the intercooler itself rather than going by the model year.

The documented fixes are straightforward: an auxiliary transmission cooler, and on the G360, running it overfilled with 15W-40 oil, a known towing practice for that gearbox. For reference, the G360 holds 3.5 quarts.

Stock setup vs. upgrades

A first-gen that left the factory with overload springs and an auxiliary cooler already has the basics. What you add depends on the trailer. A documented 1992 W350 dually tow rig runs a B&W Turnover Ball gooseneck in the bed, a 2 in ball receiver hitch at the back, six Bull Ring tie-downs and a Tekonsha Prodigy P3 electric brake controller. Documented first-gen tow rigs also run rear air-bag helper springs with an on-board compressor, and exhaust brakes show up on those builds too. For bumper-pull work, the choices are in the hardware between truck and trailer: an adjustable ball mount with the right drop so the trailer rides level, and a weight distribution hitch when the trailer is heavy enough to call for one.

What we carry

B&W Trailer Hitches supplies most of the hitch hardware: Tow & Stow adjustable ball mounts in Standard, MultiPro/MultiFlex and Pintle versions with 2, 2.5 and 3 inch shanks, a Triple Tow ball mount, heavy-duty ball mounts, hitch balls, reducer sleeves and the WDHK4500 weight distribution hitch. Big Hitch Products adds adjustable pulling hitches in 2 and 2.5 inch. Air Lift covers the air side with the Single Load Controller II, the Heavy Duty Dual Load Controller, WirelessONE and WirelessAIR compressor systems and tanks including EZ Mount versions, a replacement on-board compressor, 2 in air spring spacers and the LoadLifter 5000 Ultimate Plus stainless steel upgrade. Lucas Oil 5th Wheel & Slider Lube handles hitch upkeep, and Calibrated Power offers its Stealth Boost Tester HD regulator for pressure-testing the intake side. Our hitches page lists every hitch brand we carry.

Fitment notes

On a first-gen, hitch fitment follows the bed and frame, not the engine. Every Cummins pickup of this generation is a long bed, in regular cab or, from 1990, Club Cab form, and Dodge never built a factory crew cab Cummins on this body. Single rear wheel versus dually D350/W350 changes what fits, and from mid-1991 the 250 Cummins trucks ride on the one-ton 350 frame, so a 1992 W250 may not take the same parts as a 1990 W250. Chassis-cab trucks are their own case. Air spring fitment follows the chassis in the same way. Verify by VIN, and have your cab, wheel setup and model year handy when you call.

Frequently asked questions

What breaks first when you tow hard with a first-gen?

The documented towing failures are heat-related and live in the transmission. Towing heat kills the input bearing on the G360 5-speed, which shows up as whine after long tows, and it overheats the A518 automatic, which shows up as slipping or burnt fluid. An auxiliary transmission cooler is the documented answer, and some tow-spec trucks had one from the factory.

Does the intercooler matter for towing?

Yes. Non-intercooled trucks from 1989 to mid-1991 run higher EGT when towing and creep up on grades. The air-to-air intercooler that arrived mid-1991 significantly improves cooling and towing capability, even though the advertised 160 hp and 400 lb-ft rating stayed the same. Check for the intercooler itself, since the change came mid-year.

Will these hitches fit my Club Cab or dually?

Hitch fitment follows the bed and frame, not the engine. All first-gen Cummins pickups are long beds, but single rear wheel and dually trucks differ, and 250 trucks built from mid-1991 sit on the one-ton frame. Ball mounts, balls and weight distribution hardware go into a receiver, so the real question is which receiver your truck has. Verify by VIN or call us.

Do I need air bags to tow with a first-gen?

Not always. Tow-spec trucks were documented with factory overload leaf springs, and documented first-gen tow rigs add rear air-bag helper springs with an on-board compressor on top of that. The Air Lift controllers, compressors and tanks here run that kind of system. If you tow heavy and often, it is worth a look.

What does a documented first-gen tow rig run?

One 1992 W350 dually runs a B&W Turnover Ball gooseneck, a 2 in ball receiver hitch, six Bull Ring tie-downs and a Tekonsha Prodigy P3 brake controller, plus rear air bags. The survivor D250 that hauled hot-shot loads for 101,000 miles in 11 months did it with an auxiliary transmission cooler. Both trucks point the same way: get the hitch right, then manage heat.

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.