This is the Holset 3593681H, a new HX35 turbocharger made by Holset (Cummins Turbo Technologies). Catalogs list it for the Cummins 6CT in marine service. It crosses to Holset 3593680 and 3593681 and to Cummins 4025043. Holset files it with its fixed geometry turbos, which means it is not a variable geometry (VGT) unit. Cummins describes its own number for this turbo, 4025043, as an HX35 wastegate turbocharger.

Marine turbos live a hard life. Salt air, long hours at high load and water getting back up the exhaust all shorten it. They are replaced for a seized or dragging rotor, shaft play, oil leaks at the compressor or turbine end and corrosion of the housings. The HX35 name covers many different turbos, and most of them are for trucks and equipment, so this one has to be matched by the assembly number on the data plate.

Specifications

Fits / Applications

• Cummins 6CT marine engine with the Holset HX35 turbocharger
• Old turbo data plate reads 3593680 or 3593681, or the Cummins part number is 4025043
• Confirm by engine serial number and CPL

Fit new gaskets, prime the turbo with clean engine oil and check the oil feed and drain lines for restriction. On a boat, find out how the old turbo failed before you fit the new one. Water coming back through the exhaust will ruin a new turbo quickly.

Part Numbers & Cross Reference

Holset 3593681H  ·  Holset 3593681  ·  Holset 3593680  ·  Cummins 4025043  ·  Cummins exchange numbers 4025043NX, 4025043RX

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

Will the 3593681H fit a 6CT in a truck or a tractor?

Catalogs list it only for the marine Cummins 6CT. Other 6CT engines are listed with other Holset assembly numbers. Call 530-668-0818 with your engine serial number and the number on your turbo data plate and we will match it.

What numbers does the 3593681H cross to?

Holset 3593680 and 3593681 and Cummins 4025043, along with the Cummins exchange numbers 4025043NX and 4025043RX.

Is it a wastegated turbo?

Holset files it as a fixed geometry HX35, which only means it is not a variable geometry turbo. Cummins describes its own number for this turbo, 4025043, as an HX35 wastegate turbocharger. Compare the new turbo with your old one before you fit it.

Is it new or remanufactured?

It is a new turbocharger made by Holset, the turbo division of Cummins.

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.