Cummins ISX, QSX Inframe Engine Re-Ring Kit, New (MCB4376168)

New Inframe Re-Ring Kit for Cummins ISX and QSX Diesel Engines, Part Number MCB4376168

Why Choose This Cummins ISX, QSX Re-Ring Kit From 4BTdiesel?

• Every component in the kit is brand new, built to OEM specifications and tolerances
• Manufactured with state-of-the-art tooling and machining for supreme quality and consistency
• Components are pressure and vacuum tested for quality assurance before they ship
• Parts come ready to install with specifications already within proper tolerances
• No core charge required on any component in this kit
• Backed by an industry leading 6-month warranty from 4BTdiesel
• Available in standard and undersized bearing options to match your specific engine condition
• Fits Cummins ISX Single Cam, ISX Dual Cam, QSX Single Cam, and QSX Dual Cam engine families
• CPL/ESN Prefix fitment covers 3349, 3490, 3491, 3606, 3719, 3938, 3939, 4585, and 4588

What Is the Difference Between a Re-Ring Kit and a Full Rebuild Kit?

When an ISX or QSX shows signs of wear, not every situation calls for a full overhaul with new liners and pistons. In some cases, the cylinder bores are still within serviceable tolerances and the pistons are in good condition, but the piston rings have worn to the point where they can no longer maintain proper combustion seal. This is where a re-ring kit delivers real value. Rather than replacing the entire piston and liner assembly, a re-ring procedure installs fresh piston rings onto the existing pistons within the existing bores, restoring compression, reducing blowby, and recovering lost oil control without the full cost of a complete inframe rebuild.

This approach works best on engines where a careful inspection confirms the bores are within spec, the pistons show no scoring or damage, and the primary symptom is blowby, oil consumption, and loss of compression rather than liner wear or piston damage. If a cylinder bore measurement reveals wear beyond tolerance, a full inframe rebuild kit with new liners and pistons is the right call. 4BTdiesel’s professionally certified factory mechanics can help you evaluate which kit is appropriate for your engine’s condition before you order.

What Is Included in This Cummins ISX, QSX Re-Ring Kit

This kit covers all of the components needed for a complete ISX or QSX inframe re-ring procedure. The contents include six Cylinder Liner Kits (M-4376168), one Upper Engine Gasket Set (M-4352144), six Piston Ring Sets (M-4309441), twelve Retainer Rings (M-3064305), six Connecting Rod Bearings (M-4089405), one Main Engine Bearing Kit (M-5406110), one O-Ring Seal (M-3678756), one Pressure Relief Valve (M-4357177), and one Oil Pan Gasket (M-4026684).

Rod bearing size and main bearing size are both required selections at checkout, with options including standard, .010, .020, .025, .030, and .50 to accommodate engines at different stages of wear or that have been previously machined. Selecting the correct bearing sizes is critical to a successful re-ring, and 4BTdiesel’s professionally certified factory mechanics can help you determine the right specification before the order ships.

This kit weighs 137 lbs and ships in a 48 by 42 by 24 inch package. Because diesel engine parts are engine specific, entering your Engine Serial Number or VIN on the product page before ordering allows 4BTdiesel’s team to confirm that this kit is the correct fit for your ISX or QSX application based on your CPL or ESN prefix. Confirmed fitment prefixes include 3349, 3490, 3491, 3606, 3719, 3938, 3939, 4585, and 4588.

Get Your Cummins ISX, QSX Re-Ring Kit From 4BTdiesel

At $1,978.93 with no core charge, a 6-month warranty, and same-day shipping on in-stock orders placed by 2PM EST, this re-ring kit is a cost-effective path to restoring ISX or QSX performance without the full expense of a complete inframe overhaul. Financing is available through PayPal Pay Later and Sezzle for qualified buyers, with PayPal Pay Monthly offering 3, 6, 12, or 24 month payment plans with $0 down to help manage the cost of the repair without extending downtime any further than necessary.

Order your Cummins ISX, QSX Inframe Engine Re-Ring Kit (MCB4376168) from 4BTdiesel today.

Frequently Asked Questions About Cummins ISX QSX Inframe Re-Ring Kit (MCB4376168)

1. What engines does re-ring kit MCB4376168 fit?

This kit is built for Cummins ISX and QSX diesel engines, covering ISX Single Cam, ISX Dual Cam, QSX Single Cam, and QSX Dual Cam engine families. Confirmed CPL/ESN prefix fitment includes 3349, 3490, 3491, 3606, 3719, 3938, 3939, 4585, and 4588. 4BTdiesel recommends submitting your Engine Serial Number or VIN before ordering so our team can verify fitment for your specific engine build.

2. What is included in this re-ring kit?

The kit includes six Cylinder Liner Kits (M-4376168), one Upper Engine Gasket Set (M-4352144), six Piston Ring Sets (M-4309441), twelve Retainer Rings (M-3064305), six Connecting Rod Bearings (M-4089405), one Main Engine Bearing Kit (M-5406110), one O-Ring Seal (M-3678756), one Pressure Relief Valve (M-4357177), and one Oil Pan Gasket (M-4026684).

3. What is the difference between a re-ring kit and a full inframe rebuild kit?

A re-ring kit replaces the piston rings, bearings, seals, and gaskets while reusing the existing pistons and cylinder bores, provided those components are still within serviceable tolerances. A full inframe rebuild kit adds new cylinder liners and pistons to the scope. A re-ring is appropriate when bore wear is within spec and the primary issues are blowby, oil consumption, and low compression caused by worn rings rather than liner or piston damage.

4. How do I know if my ISX or QSX needs a re-ring kit or a full rebuild kit?

The answer comes down to bore and piston measurements taken during teardown. If the cylinder bores measure within OEM tolerance and the pistons show no scoring, cracking, or damage, a re-ring kit is a cost-effective solution. If bore wear exceeds tolerance or the pistons are damaged, a full inframe rebuild kit with new liners and pistons is the correct choice. 4BTdiesel’s professionally certified factory mechanics can help you evaluate which option fits your engine’s condition.

5. What bearing sizes are available for this kit?

Both rod bearing size and main bearing size are required selections at checkout. Available sizes are standard, .010, .020, .025, .030, and .50, covering engines at various stages of wear or previous machining. If you are unsure which size your engine requires, 4BTdiesel’s team can help you determine the correct specification before the order is placed.

6. What OEM part numbers does MCB4376168 cross reference?

This kit cross references 5472970, KIFX15/5722, KIFX155722, MCB4376168-1, MCB4376168-1CA, MCB4376168-3, MCB43761681, MCB43761681CA, and MCB43761683.

7. Is there a core charge on this re-ring kit?

No. This Cummins ISX, QSX Inframe Re-Ring Kit carries zero core charge. There is nothing to return and no additional deposit required at checkout regardless of which bearing sizes you select.

Warranty

6-month warranty.

9. How fast will this kit ship?

In-stock orders placed by 2PM EST ship the same day, Monday through Friday. The kit weighs 137 lbs and ships in a 48 by 42 by 24 inch package, so freight delivery timelines will vary by location. Plan shipping logistics in advance given the size of the package.

10. Can I finance the purchase of this re-ring kit?

Yes. 4BTdiesel offers financing through PayPal Pay Later and Sezzle at checkout. PayPal Pay Monthly provides 3, 6, 12, or 24 month payment options with $0 down for qualified buyers, making the $1,978.93 investment in your ISX or QSX re-ring much easier to manage without delaying the repair or extending downtime.

Included Components