Description

Cummins 4BT / QSB 3.3 Engine Overhaul Rebuild Kit Complete In-Frame Solution for Komatsu Applications Restore the power, reliability, and efficiency of your Cummins 4BT 3.3 QSB3.3 turbocharged diesel engine with this comprehensive overhaul rebuild kit . Designed for 8-valve configurations and compatible with multiple Komatsu construction machines , this kit includes all the precision-engineered components required for a complete in-frame rebuild. Whether you operate wheel loaders , excavators , or wheel excavators , this kit ensures OEM-level fit and performance, reducing downtime and extending engine service life. Kit Contents This premium rebuild kit includes every critical wear component needed for a proper overhaul: Cylinder Liners – Semi-finished for precise machining and fitment Overhaul Gasket Kit – Complete set of seals and gaskets for reassembly Pistons (Standard Size) – OEM-equivalent, engineered for strength and durability Piston Pins – High-strength connections between piston and rod Snap Rings – Secure piston pin placement Rod Bushings – Restores proper rod-to-crank fitment Piston Rings (Standard) – Ensures proper sealing and compression Main Bearings – Maintains crankshaft stability Connecting Rod Bearings – Reduces journal friction and wear Thrust Washers – Controls crankshaft end-play Intake & Exhaust Valves – Restores airflow and combustion efficiency Valve Guides – Ensures correct valve alignment and reduces oil leakage Intake & Exhaust Valve Seats – Maintains precise sealing in combustion chamber Engine & Piston Variations Covered Cummins QSB3.3 Turbocharged, 8-Valve – Piston 4941139 Cummins 4BT 3.3 QSB Turbocharged, 8-Valve – Piston 4944477 Cummins QSB3.3 Turbocharged, 8 Valves Piston 4941139 Cummins 4BT 3.3 QSB Turbocharged 8 Valves Piston 4944477 Komatsu Engines: SAA4D95LE Komatsu Wheel Loaders: WA90-6, WA100M-6 Komatsu Excavator: PC88MR, PC118MR-8 Komatsu Wheel Excavator: PW118MR-8   Why Choose Our Cummins 4BT / QSB 3.3 Rebuild Kit? OEM-Grade Quality: All components meet or exceed original specifications Comprehensive Coverage: Includes all internal wear parts needed for a full in-frame overhaul Application-Specific Fit: Engineered for precise fitment in Cummins-powered Komatsu equipment Performance Restoration: Regains lost horsepower, improves compression, and reduces oil consumption Durability for Heavy-Duty Use: Built for high-load, high-hour industrial and construction environments   Common Signs You Need an Overhaul Blue or white exhaust smoke Excessive oil usage Loss of compression and engine power Unusual knocking or tapping noises Hard starting or rough idle   FAQs Will this kit fit both 4BT and QSB3.3 engines? Yes, this kit is designed for both Cummins 4BT 3.3 and QSB3.3 turbocharged, 8-valve engines, covering piston part numbers 4941139 and 4944477. Is this kit suitable for in-frame rebuilds? Yes, all components are designed for in-frame overhauls, allowing you to rebuild the engine without complete removal. Are machining services required for the cylinder liners? The liners are semi-finished and require final machining to ensure precise fitment and clearances. Does the kit include turbocharger parts? No, turbocharger components are not included. This kit focuses on internal engine wear parts. How long will the rebuilt engine last with this kit? With proper installation, maintenance, and operation, service life can exceed 10,000+ operating hours.