International LT replacement engines & transmissions
International LT Engines & Transmissions
International launched the LT Series in 2016 and has changed its powertrain twice since, from Cummins X15 power to the Navistar A26 and then the S13 Integrated Powertrain. Send us your VIN and unit details and we search for a matching used replacement.
Engine families
Engines to check
Transmission families
Transmissions to check
All International trucks
Factory options varied by model and year. Links are starting points, not a fitment guarantee — we confirm against your VIN and serial numbers.
01LT engines by era
International launched the LT Series on September 30, 2016 with the 2017 Cummins X15. At launch, Navistar said its 2017 N13 engine would follow in the spring. Navistar unveiled its 12.4-liter A26 engine in February 2017, and trade press road-tested it in a 2018 International LT.
In August 2022 Navistar introduced the S13 Integrated Powertrain, a 13-liter engine paired with International's own T14 transmission, as the standard offering in the LT and RH, with orders opening that October. International now lists the S13 in the LT, RH, HX and HV Series at up to 515 hp.
02Transmissions in the LT
The A26 was paired with the Eaton Cummins Endurant HD 12-speed, and the 2018 LT that HDT tested with the A26 used an Eaton Fuller Advantage 10-speed automated manual. The S13 Integrated Powertrain uses the T14, an in-house 14-speed overdrive automated manual.
Because the T14 is designed together with the S13, an S13 truck's engine and transmission are best treated as a matched set. Send both labels if you are replacing either one.
03Matching a replacement to your LT
The LT has run three different engine families: Cummins X15, Navistar A26 and Navistar S13. They are not interchangeable without major changes to mounts, cooling, wiring, ECM and aftertreatment, and the S13 is integrated with the T14 transmission. The engine dataplate and the build data tied to your VIN tell us which family to search for.
Within a family, emissions generation also matters. An X15 from a 2017 LT and one from a later truck may use different software and sensors, so we search by engine serial number.
04What to have ready
Before you call about an LT, gather:
- Full VIN
- Engine model and serial number (Cummins X15, A26 or S13)
- Transmission label: Endurant, Eaton Fuller or T14 details
- Model year and approximate mileage of the failed unit
- Whether you need a complete engine, long block or transmission only
FAQ
International LT engine & transmission questions
Which engine does my International LT have?
Depending on year and spec, an LT can have a Cummins X15, a Navistar A26 or a Navistar S13. Check the engine dataplate or the build data tied to your VIN.
Can I swap an A26 for an S13 or an X15?
That is a major conversion involving mounts, cooling, wiring, ECM, aftertreatment and often the transmission. Plan it with your shop before ordering. We search for the engine that matches what is in your truck unless you tell us otherwise.
Do you source T14 transmissions?
We can search for one. The T14 is designed as part of the S13 Integrated Powertrain, so send the transmission label, engine serial and VIN.
Was the LT built with a MaxxForce engine?
The LT launched in 2016 with the Cummins X15 and later used Navistar's A26 and S13. If your truck has a different engine, send the engine tag details and we search accordingly.
Are you an International dealer?
No. We are an independent sourcing company. We search supplier sources nationwide and confirm availability and freight on your quote.
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Ready when you are
Replacing the engine or transmission in your International LT? Start with the VIN.
Have your engine serial number, CPL and VIN handy. If you don't, we'll help you find them.
Commercial-Engines.com is an independent supplier of used commercial truck engines and transmissions. Manufacturer names, model names and part numbers are used for identification only and do not imply affiliation with, or endorsement by, any manufacturer. Read the full disclaimer.