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Cummins ISM M11 turbo HX55 3536995 front view

HX55 3536995 3590044 Turbocharger for Cummins ISM M11 10.8L

The HX55 is a Holset fixed-geometry turbocharger for the Cummins M11 and ISM 10.8L diesel engines. No variable vanes, no electronic actuator, no wastegate on this turbo - it is a straightforward mechanical unit that relies on exhaust energy alone to build boost. The HX55 has been in service since the late 1990s and remains one of the most common turbos on M11 and ISM-powered trucks and buses still on the road. Holset part 3536995 is the master number; the replacement assembly is 3590044. Our HX55 is built new with all new components - compressor wheel (62.9mm inducer / 97.8mm exducer), turbine wheel (86.4mm inducer), bearing housing, and both housings - dynamically balanced and shipped with gaskets. We supply shops, fleets, and distributors.

Turbo Model

HX55 (fixed geometry, non-wastegated)

OEM / Interchange Numbers

  • 3536995
  • 3536996
  • 3590044
  • 3590045
  • 3800471
  • 3803938
  • 3536149
  • 4039173
  • 4046031
  • 2834419
  • 2834364

Application

Cummins ISM, ISME, M11 Truck and Bus; fixed geometry, non-wastegated

Service & Support

  • 1-Year Unlimited-Mileage Warranty
  • US Stock, Fast Dispatch
  • Bulk Orders Welcome
  • White-Label Support
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FAQ

The HX55 (3536995 / 3590044) fits Cummins M11, ISM and ISME 10-8L engines in trucks and buses.

No. The HX55 is a fixed-geometry turbo with no wastegate, no VGT vanes, and no electronic actuator. Boost is controlled entirely by exhaust energy. Install is straightforward - bolt on, connect oil lines, start the engine. No calibration or wiring required.

Common signs: shaft play (radial wobble or axial drag), turbo whine or rattle at idle, oil in the intake boot or charge-air cooler, black or blue smoke under load, and loss of boost at rated power. Grab the compressor wheel and check for play before ordering.

Brand new, 100% new components, dynamically balanced. Ships with gaskets. No core charge. One-year unlimited-mileage warranty.

OE and interchange numbers include 3536995, 3536996, 3590044, 3590045, 3800471, 3803938, 3536149, 4039173, 4046031, 2834419, 2834364. If your number is not listed, send it with the old part's dataplate photo and we confirm the match before shipping.

Yes. US stock, volume pricing for shops, fleets, rebuilders, and distributors.

HX55 Turbo for Cummins M11 and ISM: A Reliable Workhorse

The Cummins M11 and ISM engines ran in tens of thousands of trucks, buses, and industrial machines from the mid-1990s through 2012. Many are still in daily service. The HX55 is the turbo that keeps them running. It is mechanically simple and durable, but after 300,000-600,000 miles, even a well-maintained HX55 will need replacing.

Key specifications

SpecValue
Compressor wheel62.9mm inducer / 97.8mm exducer
Compressor A/R0.68
Turbine wheel86.4mm inducer / 77.8mm exducer
Turbine A/R0.88
WastegateNone
VGTNo - fixed geometry
CoolingOil only
HP capability370-500+ HP

What makes the HX55 different from VGT turbos

The HX55 is a fixed-geometry turbo with no electronic components. There is no actuator, no position sensor, no wiring harness, and no calibration step during install. Boost builds in direct proportion to exhaust energy and falls off with engine speed. This simplicity is actually a major selling point for older M11 and ISM trucks: fewer parts to fail, lower replacement cost, and a faster install. If your engine ran a VGT (HE400VG or HE451VE), this is not the right turbo - check the turbo nameplate to confirm.

Common failure modes

  • Bearing wear - the most frequent failure. Oil starvation from clogged feed lines or poor oil quality accelerates it. Symptoms: shaft play, turbo whine at idle, oil in the intake tract.
  • Compressor wheel erosion - dust ingestion from a leaking air filter or loose intake clamp. The large 97.8mm exducer wheel catches debris fast.
  • Turbine housing cracks - thermal cycling over hundreds of thousands of miles. Exhaust soot at the turbo flange and reduced boost are the signs.
  • Oil seal failure - restricted drain tube or high crankcase pressure pushes oil past the seals. Blue/white smoke and rising oil consumption.

Cross Reference Numbers

This turbocharger replaces the following OE and interchange numbers:

  • 3536995
  • 3536996
  • 3590044
  • 3590045
  • 3800471
  • 3803938
  • 3536149
  • 4039173
  • 4046031
  • 2834419
  • 2834364

Related configuration: HX55 4089754 for ISX Signature 450.

Installation and Care

  • Find out why the old turbo failed before installing the new one. Oil starvation or contaminated oil will destroy the replacement the same way.
  • Change the engine oil and filter. Flush or replace the oil feed line.
  • Replace the oil drain gasket and inspect the drain tube for carbon buildup or kinks.
  • Check the air filter, intake ducting and charge-air connections for leaks or debris.
  • Prime the turbo with clean oil before startup. No electronic calibration is required.

See our quality process for details.

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