Description
Cummins ISX In-Frame Rebuild Kit, New (5579309)
Complete In-Frame Rebuild Kit for Cummins X15 Engines
When your Cummins X15 diesel engine starts showing signs of internal wear, low compression, increased oil consumption, or reduced performance, this new in-frame rebuild kit – part number 5579309 offers a comprehensive solution. Designed to restore your engine’s core components to like-new condition, this kit includes all the essential parts needed for a quality in-frame overhaul.
Why Choose This Cummins X15 Rebuild Kit?
New Components – No Reman or Used Parts
This rebuild kit features all new, premium components manufactured to precise tolerances for a reliable rebuild. Unlike kits that re-use old parts, every item in this kit is engineered to match or exceed OEM quality standards, ensuring longevity and consistent performance.
Restores Engine Performance & Compression
Over time, high-mileage engines suffer from worn bearings, seals, liners, and gaskets, leading to loss of compression and power. By replacing these components with new parts, this kit helps restore proper combustion and engine efficiency – improving power output and reducing fuel consumption.
Engineered for Heavy-Duty Use
Built with heavy-duty applications in mind, this kit supports engines that undergo significant loads and high-hour service. Whether for fleet vehicles or long-haul trucks, the quality components help improve engine uptime and reliability.
What’s Included in the Kit
This Cummins X15 in-frame rebuild kit (5579309) provides a complete set of new parts necessary for a thorough engine overhaul – enabling you to rebuild the engine without sourcing individual components separately:
- Cylinder Kits (includes liners, pistons, piston rings, wrist pins, and retainers)
- Gasket & Seal Set for full in-frame coverage
- Main & Rod Bearing Sets
- Thrust Washers and Bearings
- Oil Seals and O-Rings
- Valve Stem Seals and related hardware
- Installation Hardware & Bearings
Each component is precision-manufactured to ensure accurate fitment and durability – designed to help your ISX engine return to optimal operating condition.
Benefits of an In-Frame Rebuild
Restore Compression & Power
Replacing worn internal parts restores proper compression and combustion efficiency, helping your ISX engine perform closer to its original factory power levels.
Improve Oil Pressure & Reduce Wear
New bearings and seals promote better oil pressure control, reducing internal wear and enhancing overall lubrication throughout the engine.
Extend Engine Life
By renewing critical engine components, an in-frame rebuild renews lost performance and significantly extends your engine’s service life.
Cost-Effective Alternative to Engine Replacement
A full engine replacement can be costly and time-consuming. Rebuilding the existing engine with this kit delivers OEM-level performance and durability at a more affordable cost, reducing downtime and expense for heavy-duty operations.
Common Symptoms You Need a Rebuild
Knowing when to rebuild your Cummins X15 engine can save you from further damage. Watch for these indicators:
- Excessive oil use or leaks
- Low engine compression or misfires
- Loss of power or reduced acceleration
- Metal debris in oil or frequent overheating
Addressing these issues early with a quality rebuild kit can prevent more costly engine failures down the road.
Frequently Asked Questions: ISX Engine Rebuild Kit
What engines is this kit compatible with?
This in-frame rebuild kit is designed for Cummins X15 diesel engines, making it suitable for many heavy-duty on-road and vocational applications.
Are all parts new?
Yes – this kit includes only new components manufactured to high quality standards, ensuring reliable rebuild results.
Why choose an in-frame rebuild kit?
An in-frame rebuild kit lets you overhaul the core internal parts without removing the engine from the frame, saving time and labor costs compared to an out-of-frame rebuild or full engine replacement.
Can this kit help reduce maintenance costs?
Absolutely – by restoring worn components and preventing failures, this kit can lower long-term maintenance and reduce unscheduled downtime.
Maximize Your Engine’s Life & Efficiency
When your Cummins X15 engine needs a reliable rebuild solution, the 5579309 in-frame rebuild kit delivers the parts, quality, and performance you need for a successful overhaul. Engineered for durability and built with precision, this kit helps you restore engine performance, extend service life, and get back on the road with confidence.















