This is the Holset 3786775HX, an HE351VE variable geometry turbocharger for the Cummins ISB 6.7L, remanufactured by Holset (Cummins Turbo Technologies). It is a complete turbo and comes with the electronic actuator fitted. It replaces 4955399, 4955401 and 5322096, along with 2837248, 2837250, 2839140, 2839150, 3791778 and 3791781. The new version of the same turbo is Holset 3786775H, and Holset sells the HE351VE without the actuator as 3791866HX.

The HE351VE moves a sliding nozzle to control boost and exhaust braking. Soot makes the nozzle stick, and the actuator fails on its own too. Either one gives low power, a weak or dead exhaust brake and turbo actuator fault codes. A turbo with a seized nozzle, shaft play or oil in the charge pipes needs replacing, not just an actuator. A refundable core applies.

Specifications

Fits / Applications

• Cummins ISB 6.7L with the Holset HE351VE turbocharger
• Old turbo tag reads 3786775, 4955399, 4955401, 5322096, 5325897, 5325899, 3771639, 4044383, 4044390, 2837248, 2837250, 2839140, 2839150, 3791778 or 3791781
• Confirm by engine serial number

Fit new gaskets, flush or replace the oil feed line, check the oil drain and the actuator coolant lines, and prime the turbo with clean engine oil before the first start. Clear the fault codes and find the cause of the old failure, such as soot loading, a blocked exhaust aftertreatment system or oil contamination.

Part Numbers & Cross Reference

Holset 3786775HX  ·  Holset new version 3786775H  ·  Holset without actuator 3791866HX  ·  Holset / Cummins 3786775  ·  Holset / Cummins 4955399  ·  Holset / Cummins 4955401  ·  Holset / Cummins 5322096  ·  Holset / Cummins 5325897  ·  Holset / Cummins 5325899  ·  Holset / Cummins 3771639  ·  Holset / Cummins 4044383  ·  Holset / Cummins 4044390  ·  Holset / Cummins 2837248, 2837250, 2839140, 2839150, 3791778, 3791781  ·  Cummins remanufactured numbers 4955399RX, 4955399NX, 4955401RX, 4955401NX

Cross-reference numbers can change with engine serial, build year and emissions tier, so treat this list as a starting point. Send us your engine serial number and we will confirm the exact match against your build before anything ships. That check is free and takes a few minutes.

Frequently Asked Questions

Does the 3786775HX come with the actuator?

Yes. It is a complete HE351VE turbocharger with the electronic actuator fitted. Holset sells the HE351VE without the actuator as 3791866HX.

What numbers does the 3786775HX replace?

It replaces 3786775, 4955399, 4955401 and 5322096, and catalogs also cross 2837248, 2837250, 2839140, 2839150, 3791778 and 3791781 to it. The new version of the same turbo is Holset 3786775H.

Will it fit my 6.7L Cummins?

It fits the ISB 6.7L engines built with this HE351VE assembly, and not every 6.7L uses the same one. Call 530-668-0818 with your engine serial number and the old turbo tag number and we will confirm it.

Is it new or remanufactured, and is there a core?

It is remanufactured by Holset. A refundable core charge applies, and it comes back when we receive your old turbo.

Related Parts

• Cummins ISB 6.7L Midrange HE351VE Turbocharger with Actuator | Holset 3786778HX Remanufactured
• Cummins ISB 6.7L HE300VG Turbocharger without Actuator | Alliant Power AP90045 Remanufactured
• Cummins ISB 6.7L EPA21 HE300VG Turbocharger with Actuator | Alliant Power AP90969 Remanufactured
• Komatsu SAA6D107E, SAA4D107E & Cummins QSB6.7 CP3 Fuel Pump | Bosch 0445020109 New (Cummins 4989266)

Why Buy From Valley Fuel Injection

We are a diesel fuel-injection and turbocharger shop in Woodland, CA, rebuilding pumps, injectors and turbos on our own benches since 1993, not a drop-ship storefront. When you call, you talk to the people who test these units. We verify fitment against your engine serial, VIN or build date before anything ships, so the right part arrives the first time.