What The 4036892 Is
This is a fixed-geometry, non-wastegated HX55 turbocharger for the EGR-era Cummins ISX1 and ISX Signature 450 (NON-ESR). No wastegate actuator, no variable vane cartridge, no electronic actuator to calibrate. Exhaust gas drives the turbine, the compressor feeds the charge air cooler, and boost is controlled by the fixed A/R housing and the engine's fuel map. Simple, and durable when the oil supply stays clean.
It shows up in Class 8 chassis that ran the ISX: Freightliner Cascadia, Columbia and Coronado, Kenworth T680, T800 and W900, Peterbilt 389 and 579, International ProStar, Volvo VN and VNL in pre-2010 form, and Western Star 4900. Chassis alone does not settle it. The engine serial number and the tag on the old turbo do.
Critical point before you buy: do not substitute this fixed-geometry unit into a wastegated HX55W application. The mounting looks close enough to fool you on the bench, but the boost control strategy is different and the ECM will not be happy. Confirm which HX55 variant the engine left the factory with.
Why These Numbers Cross
The ISX platform was built over a long production run and Cummins revised the HX55 service package more than once. Same turbine wheel, same compressor stage, same mounting pattern, different box and different supersession level. That is why 4036892 lands on the same physical turbocharger as the later service numbers, and why a parts counter can hand you a different number for the identical unit.
The Cummins service listings you will see are 4089754NX and 4089754RX. The NX suffix is a new-exchange unit and the RX suffix is a remanufactured core-exchange unit. Both describe the same turbocharger configuration for this application, just different build routes and different core handling requirements at the counter.
PartStop is not affiliated with or authorised by Cummins. Those numbers are listed here for identification only, so you can match what is stamped on the turbo tag or printed on the invoice from the last replacement. This aftermarket unit is a direct replacement built to the same fixed-geometry HX55 configuration.
Check Before You Order
Pull the tag off the old turbo first. Cummins turbo tags sit on the compressor housing or the bearing housing, and the number on that tag beats any catalogue lookup. Write down the engine serial number off the dataplate as well. Between the two you can confirm whether the truck runs the fixed-geometry HX55 or the wastegated variant.
Then find out why the old one failed. Bearing failure from oil starvation, coked oil in the drain line, a shaft that shows radial play, or compressor wheel damage from something that came through the air cleaner. If debris ate the wheel, the intake tract and charge air cooler need cleaning or the new turbo eats the same debris. Replace the oil feed line and prime the bearing housing on install.
4036892 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 4036892. Use them to identify the part — then confirm the exact fit by VIN or the number stamped on your old unit before you order. An interchange is a starting point, not a fitment guarantee.
| Brand / Line | Cross-Reference Numbers |
|---|---|
| Cummins (New-Exchange) | 4089754NX |
| Cummins (Reman) | 4089754RX |
Frequently asked questions
Is 4089754RX the same turbo as 4036892?
They cross to the same fixed-geometry HX55 configuration for the ISX1 and Signature 450. The RX suffix indicates a remanufactured core-exchange unit and NX indicates new-exchange. Those numbers are listed for identification only. Confirm against the tag on your existing turbo before ordering.
Will this fit a wastegated HX55W ISX?
No. This is the fixed-geometry, non-wastegated version for the pre-2010 EGR-era ISX1 and Signature 450 NON-ESR. The wastegated HX55W uses a different boost control setup and should not be substituted. Check the engine serial number and the old turbo tag to identify which variant you have.
Do I need to replace the oil feed line with the turbo?
Strongly recommended. Coked or partially blocked oil supply lines are a common cause of repeat bearing failure on the ISX, and the new turbo will fail the same way if the restriction stays. Flush or replace the feed and drain lines, and prime the bearing housing with clean oil before first start.
Not sure it fits? We check before you pay.
Run your VIN and we’ll match parts to your exact truck, or call the counter — a person who knows trucks verifies fitment by OEM number before the order ships. No wrong-box returns.
More cross-reference guides
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Every part below is a Premium Quality aftermarket Direct Replacement with published OEM cross-reference numbers, a 6+ month warranty and same-business-day shipping from Tacoma, WA. Not sure it fits? Run your VIN — or call and a person who knows trucks will verify fitment before you pay.