CUMMINS 3923178 OEM COMPRESSOR OUTLET ELBOW (AIR TRANSFER PIPE) – HX35/HY35/HX40 – 5.9L (1994–2002)

The CUMMINS 3923178 OEM COMPRESSOR OUTLET ELBOW (AIR TRANSFER PIPE) is the factory-style turbo outlet elbow used on 1994–2002 Dodge Ram 2500/3500 5.9L Cummins engines with Holset HX35, HY35, and HX40 turbochargers. This genuine Cummins air transfer pipe restores proper compressor outlet geometry, seals with the correct V-band and O-ring, and keeps your charge air routing tight, leak-free, and ready for stock or mild performance upgrades.

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Fitment

• Vehicle: 1994–2002 Dodge Ram 2500/3500 with 5.9L B/ISB Cummins diesel
• Turbocharger compatibility (light-duty truck focus):
  • Holset HX35 (OE turbo on most 1994–2002 trucks)
  • Holset HY35 (select 24-valve 5.9L applications)
  • Holset HX40 (common performance/HD replacement with OE-style compressor outlet)
  • Select S300 variants using an OE-style 3.0" V-band compressor cover
• Engine family usage (broader Cummins B/ISB coverage):
  • Various 4B/6B/ISB/ISD/ISF/B6.7 applications where Cummins specifies air transfer pipe 3923178.
• Outlet size: 3.0" hose interface for intercooler tube/coupler
• Quantity: 1 elbow required per turbocharger (sold individually)

Why Choose Genuine Cummins 3923178

• Direct OE replacement – Factory geometry and sealing surfaces for OE or OE-style Holset turbos.
• Correct V-band & O-ring interface – Designed to use Cummins outlet clamp and O-ring for a leak-free seal.
• Durable construction – OEM material, wall thickness, and bends for long service life under heat and boost.
• Supports performance upgrades – Works with many HX35/HX40 drop-in and S300 OE-cover setups that retain the stock outlet arrangement.
• Backed by Cummins – Genuine Cummins part sourced by CPP Diesel, not a generic aftermarket elbow.

Often Paired With (Hardware)

• Compressor outlet V-band clamp: Cummins 3923060 / 3069053 (not included)
• Compressor outlet O-ring: Cummins 3883284 (not included)
• 3.0" intercooler hose and T-bolt clamps (replace if aged, oil-soaked, or cracked)

Cross-Reference & Related Genuine Cummins Parts (CPP Diesel)

For a complete OE-style turbo outlet system on your 1994–2002 Ram 5.9L Cummins, pair this elbow with these genuine Cummins components available on cppdiesel.com:

• CUMMINS 3927811 OEM EXHAUST OUTLET ELBOW (HX35) – RAM 5.9L (1994–2002) – OE turbine outlet elbow for HX35 downpipe connection.
• CUMMINS 3535001 OEM HX35 TURBO OUTLET GASKET (5-BOLT) – 5.9L (1994–2002) – Seals the HX35 turbine housing to the 5-bolt exhaust outlet elbow.
• CUMMINS 3575169 OEM HX35/HX40 TURBOCHARGER REBUILD KIT – 5.9L CUMMINS (1994–2002) – Genuine Cummins kit with bearings, seals, clips, and O-rings for HX35/HX40 service.

Specifications

Installation Notes

• Always install with a new Cummins 3883284 O-ring in the compressor cover groove.
• Use the correct Cummins V-band clamp (3923060 / 3069053) and torque evenly to avoid leaks.
• Verify the intercooler tube alignment; do not force the elbow into position against the hose.
• Inspect and replace aged or oil-soaked 3.0" intercooler couplers and clamps as needed.

Frequently Asked Questions

Yes, if you are running a Holset HX35, HY35, or HX40 turbocharger with the factory-style compressor cover. This is the OE-style compressor outlet elbow (air transfer pipe) used on 5.9L B/ISB engines in 1994–2002 Ram 2500/3500 trucks. If your truck has a non-stock turbo or custom cover, verify that it accepts the OE 3923178-style V-band outlet before ordering.

The 3923178 elbow is designed primarily for Holset HX35, HY35, and HX40 units using the OE-style 3.0" V-band compressor outlet. It will also work with select S300 turbos that are machined to accept the stock Cummins/Holset V-band elbow and retain a 3.0" outlet. If your S300 or other aftermarket turbo uses a different outlet or bolt-on elbow, this part may not fit.

At minimum, install a new compressor outlet O-ring (Cummins 3883284) and the correct V-band clamp (Cummins 3923060 / 3069053). Many owners also pair this elbow with a fresh exhaust outlet elbow and gasket:

• Exhaust outlet elbow: CUMMINS 3927811 OEM EXHAUST OUTLET ELBOW (HX35)
• Turbo outlet gasket: CUMMINS 3535001 OEM HX35 TURBO OUTLET GASKET (5-BOLT)

If you’re refreshing an older HX35/HX40, consider the Cummins 3575169 OEM TURBOCHARGER REBUILD KIT at the same time.

Yes, as long as your cold-side intercooler piping still uses a 3.0" coupler at the turbo outlet and the piping is indexed to meet the OE elbow position. Many aftermarket charge-pipe kits are designed to work with the factory 3923178-style elbow. If your kit includes its own turbo outlet elbow, follow the kit manufacturer’s directions instead.

This is a genuine Cummins OEM air transfer pipe, part number 3923178, supplied by CPP Diesel. It is not a generic or private-label replacement. Genuine Cummins parts help maintain original fit, sealing, and durability, and are the best choice when you want OE reliability on a 5.9L Ram work truck, tow rig, or daily driver.