1998.5-2002 Dodge 5.9L Cummins Turbo Accessories

Turbo accessories on the 1998.5-2002 RAM 5.9L Cummins

The factory turbo is a single wastegated Holset: the HX35W on 1998.5-1999 trucks and manual trucks, the HY35W on 2000-2002 automatics. Charge air runs through rubber boots to a front-mounted intercooler. Most of what lives in this collection keeps that system sealed, oiled and cool, or helps you install a turbo the right way. When an HY35W is rebuilt, the parts involved are the bearing cartridge, seals and washers, turbine shaft, compressor wheel, oil supply and drain tubes, and Marman clamps.

What fails and why

Boost leaks come first. Rubber intercooler boots crack with age or slip under their clamps, and the truck turns doggish, smokes and runs high EGT. Silicone boots with spring-loaded clamps stop the chronic blow-off. On the turbo itself, high-mileage wear shows as compressor-wheel blade erosion from poor air filtration, oil-seal wear on the turbine shaft and journal-bearing wear. The signs are oil in the intake or intercooler, shaft play, a whistle or lost boost. One more: a boost elbow raises wastegate pressure and commonly sets P0234 on a stock calibration.

What we carry

• Gaskets: MAHLE turbo inlet gasket and mounting gasket set for the 5.9L, the undivided T3 mounting gasket, and T4 and T6 flange gaskets.
• Oil supply and drain: the Fleece Performance Engineering replacement oil feed line and factory oil feed fitting for Holset turbos, the Fleece HX35 installation kit, and a PPE T4 oil drain fitting.
• Clamps and mounting: Turbosmart constant tension clamps, plus a BD Diesel high torque hose clamp, exhaust V-band clamp and turbo mounting kit.
• Heat: turbo blankets from PPE (titanium woven T4 and T6), Mishimoto and ATS Diesel Performance, plus the BD Cool Down Timer 2.
• Testing: the Calibrated Power Solutions Stealth Boost Tester HD regulator, with inlet adapters for Holset and S300/S400/S500 compressors.
• Boost and cooling: a Dynomite Diesel boost elbow, Banks Power Quick Turbo systems, and a Mishimoto radiator and transmission cooler bundle.

For complete turbos, see our turbos page or the Cummins hub.

Fitment notes

Gaskets and adapters are flange-specific, so match T3, T4 or T6 to the turbo you run. Many aftermarket turbos use an HX40-style downpipe flange. Several parts here are listed for wider ranges, such as 1991-2018 or 1994-2022 5.9/6.7L Cummins, so read the title. On a California-registered truck, confirm a CARB EO for any boost-raising part. Verify by VIN.

Frequently asked questions

How do I find a boost leak on a second-gen Cummins?

Pressurize the intake side with a boost tester and check the intercooler boots and clamps. A cracked or slipped boot is the classic cause of low power, smoke and high EGT on these trucks. Spring-loaded clamps help keep boots from blowing off again.

What should I replace when I pull the turbo?

Plan on fresh mounting and inlet gaskets, and check the oil supply and drain lines and their fittings. If the turbo itself is worn, the rebuild parts are the bearing cartridge, seals and washers, turbine shaft and compressor wheel. Oil in the intake or shaft play tells you it is due.

Will a boost elbow set a code?

Commonly, yes. A boost elbow raises wastegate pressure, and on a stock calibration it sets P0234, turbo boost limit exceeded. Keep pre-turbo EGT under 1,250 F with any boost change, and read it with a manifold-mounted pyrometer.

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.