HX55 3536995 Turbocharger for Cummins ISM M11
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HX55 Turbochargers
New Holset HX55 Wastegated Turbochargers for Cummins ISM, ISX and Detroit DD15
The Holset HX55 is a fixed-geometry, wastegated turbocharger from the era before VGT took over heavy-duty diesel. No electronics, no nozzle ring vanes, no actuator calibration — just a mechanical turbo that spools, builds boost, and bleeds off excess pressure through a wastegate. The HX55 was used on three major platforms: the Cummins ISM and M11 (eleven liters), the Cummins ISX Signature (fifteen liters), and the Detroit DD15 in its early EPA10 configuration. These engines are older but far from retired — millions of trucks still run them, and turbo service at high mileage is inevitable. We stock brand new HX55 turbochargers for all three platforms, matched by Holset part number. No core charge. Shops, fleets and distributors order from US stock.
- 100% Brand New
- OEM-Spec Quality
- US Stock, Fast Dispatch
- Direct-Fit Replacement
- Exact Part-Number Match
- 1-Year Warranty
- No Core Charge
Fixed Geometry, Zero Electronics — The Pre-VGT Workhorse
The HX55 is the turbo for shops that want simplicity. No VGT codes, no actuator pairing, no scan tool calibration. Bolt on, connect oil lines, start, idle, go. The ordering challenge is that the HX55 crosses three different engine platforms with different part numbers — get the platform wrong and the turbo does not fit. We stock all three and verify before shipping.
ISM, ISX Signature and DD15 Variants
Every HX55 we ship is 100% new — new CHRA, new wheels, new wastegate mechanism. No core deposit, no old unit to freight back. On a platform this old, reman quality is a gamble — a new unit eliminates the uncertainty.
Fixed Geometry: No Vanes, No Electronics
No Scan Tool Required for Installation
The HX55 is a wastegated turbo with zero electronic components. No VGT nozzle ring to stick, no electronic actuator to fail, no scan tool required for installation. The wastegate opens mechanically at a set boost pressure. This makes diagnosis simple (shaft play, seal condition, wastegate function) and replacement straightforward.
The Turbo Before the Complexity
Trucks that run the HX55 predate the VGT era on their respective platforms. The ISM moved to the HE531VE, the ISX moved to the HE451VE, and the DD15 moved to VGT configurations. The HX55 trucks are older and simpler — and their owners often prefer it that way.
Wastegate Diagnosis Is the Whole Job
Trucks running HX55 turbos are deep into their working life — high mileage, proven platforms, kept running because they earn money. Turbo replacement at this stage is routine maintenance. Consistent wholesale pricing from US stock. See the wholesale page.
Ships New, Matched by Holset Part Number
One-year warranty on every HX55, handled by our US team. Before install, check the oil feed and drain lines for restriction and inspect the wastegate linkage for free movement. See the warranty page.
ISM, ISX Signature and DD15 Variants
Every HX55 we ship is 100% new — new CHRA, new wheels, new wastegate mechanism. No core deposit, no old unit to freight back. On a platform this old, reman quality is a gamble — a new unit eliminates the uncertainty.
Fixed Geometry: No Vanes, No Electronics
No Scan Tool Required for Installation
The HX55 is a wastegated turbo with zero electronic components. No VGT nozzle ring to stick, no electronic actuator to fail, no scan tool required for installation. The wastegate opens mechanically at a set boost pressure. This makes diagnosis simple (shaft play, seal condition, wastegate function) and replacement straightforward.
The Turbo Before the Complexity
Trucks that run the HX55 predate the VGT era on their respective platforms. The ISM moved to the HE531VE, the ISX moved to the HE451VE, and the DD15 moved to VGT configurations. The HX55 trucks are older and simpler — and their owners often prefer it that way.
Wastegate Diagnosis Is the Whole Job
Trucks running HX55 turbos are deep into their working life — high mileage, proven platforms, kept running because they earn money. Turbo replacement at this stage is routine maintenance. Consistent wholesale pricing from US stock. See the wholesale page.
Ships New, Matched by Holset Part Number
One-year warranty on every HX55, handled by our US team. Before install, check the oil feed and drain lines for restriction and inspect the wastegate linkage for free movement. See the warranty page.
WHY CHOOSE US
Simple turbo, verified supply, no complications
We match by Holset part number, hold all three HX55 variants on a US shelf, and ship fast. No actuator to pair, no calibration to schedule — just a turbo that works. More about our company and quality process.
FAQ
The HX55 is used on three heavy-duty diesel platforms: the Cummins ISM and M11 (eleven-liter), the Cummins ISX Signature (fifteen-liter, pre-VGT era), and the Detroit DD15 (early EPA10 configuration). Each platform uses a different HX55 part number with platform-specific compressor and turbine calibrations.
No. The HX55 is a fixed-geometry, wastegated turbo. It has no movable vanes, no nozzle ring, and no electronic actuator. Boost is controlled by a mechanical wastegate that opens at a set pressure threshold. This makes the HX55 simpler to diagnose and replace than VGT turbos like the HE451VE or HE400VG.
No. The HX55 has no electronic components that require calibration. Installation is mechanical: bolt the turbo to the exhaust manifold, connect oil feed and drain lines, connect intake and exhaust piping, start and idle. No scan tool, no actuator pairing, no software calibration.
No. Engines that came with VGT turbos have ECM calibrations that rely on the VGT's variable boost control for emissions compliance, EGR management and exhaust brake function. Replacing a VGT with a fixed-geometry HX55 would eliminate those functions and trigger fault codes. Replace like for like.
All units are 100% brand new. No rebuilt cores, no core charge. New CHRA, new wheels, new wastegate. Balanced and OEM-spec. One-year warranty.
Yes. Fleet operations running older ISM, ISX or DD15 trucks order HX55 turbos as routine maintenance parts. Consistent wholesale pricing from US stock. See the wholesale page.
Holset HX55 Turbocharger Guide
The HX55 belongs to Holset's HX-range — the fixed-geometry turbo family that preceded the current VGT era. Understanding what the HX55 is (and is not) helps shops diagnose correctly and avoid over-ordering.
HX55 Application Matrix
| Part number | Engine | Typical trucks |
|---|---|---|
| 3536995 | Cummins ISM / M11 | Kenworth, Peterbilt, International vocational |
| 4089754 | Cummins ISX Signature 450 | Kenworth, Peterbilt Class 8 highway |
| 2836376 | Detroit DD15 | Freightliner Cascadia, Western Star |
HX55 vs VGT: Different Eras, Different Turbos
The HX55 and the VGT turbos that replaced it on each platform are fundamentally different machines. The HX55 uses a single fixed-geometry turbine housing and controls boost by dumping excess exhaust through a wastegate. A VGT uses movable vanes to direct exhaust flow at variable angles, controlling boost continuously across the RPM range without wasting exhaust energy. The VGT also serves as the exhaust brake and assists EGR flow — functions the HX55 does not perform. Trucks that came with the HX55 relied on separate exhaust brake valves and different EGR strategies.
HX55 Failure Patterns
Without a VGT mechanism, the HX55 fails through simpler pathways:
- Bearing wear — Journal bearings develop clearance at high mileage. Shaft play increases until the wheels contact the housings. Check radial and axial play at the compressor wheel — measurable play means replacement time.
- Seal degradation — Piston ring seals on both sides harden with age. Oil leaks into the exhaust (blue smoke at startup) or intake (oil consumption and fouled charge-air cooler).
- Wastegate fatigue — The wastegate actuator diaphragm or linkage wears over time. The gate sticks open (boost loss) or closed (over-boost). Inspect the wastegate rod for free movement and check boost pressure against spec under load.
HX55 Installation: No Scan Tool Required
The HX55 install is mechanical from start to finish. Remove the old turbo (exhaust manifold bolts, oil feed, oil drain, intake and exhaust piping). Flush or replace the oil feed line — carbon restriction is the leading cause of premature bearing failure on any Cummins or Detroit turbo regardless of model. Install the new turbo, pour clean oil into the feed port, hand-spin the shaft, connect all lines, and idle the engine for several minutes to establish oil pressure and check for leaks. Verify boost pressure under load and confirm the wastegate opens at the correct pressure. No software, no calibration, no scan tool — one of the last turbo platforms where the job is purely wrench work.
