John Deere 6.404T/A Engine Overhaul Kit – ESN ≤335845

Premium Complete Engine Rebuild Solution

Bring your John Deere 6.404T/A, 6.404T and 6.404A engines back to peak performance with this OEM-quality overhaul kit. Each component is manufactured to strict tolerances for durability, long service life and smooth operation even under heavy agricultural or construction loads.

Engine Details

• Models Covered: 6.404T/A, 6.404T, 6.404A

• Serial Range: Up to ESN 335845

• Bore Size: 4.25 in / 108 mm

• Pin Diameter: 1.61 in / 41 mm

• Cylinder Liners: Semi-finished type for precise machining and perfect fit

OEM-Equivalent Replacement Numbers

• Block: R43310, R45980, R47020, R47110

Compatible Applications

• Farm Tractors: John Deere 4520, 4620, 5440

• Combines: John Deere 4320

• Wheel Loaders: John Deere 644, 644A

• Excavators: John Deere 690, 690A

• Compactors: John Deere 646, 646B

What’s Included in the Kit

• 1 Set Overhaul Gasket Kit for complete sealing

• 1 Set Semi-finished Cylinder Liners for accurate re-boring

• 1 Set Pistons STD for optimal compression

• 1 Set Piston Pins for secure piston movement

• 1 Set Snap Rings for proper piston pin retention

• 1 Set Rod Bushings for smooth connecting rod action

• Set Rings for 6 Pistons STD for excellent oil control

• 1 Set Main / Con Rod Bearings for crankshaft support

• 1 Set Thrust Bearings for axial load protection

Why Choose This Overhaul Kit?

• Designed for maximum engine life and OEM-level reliability

• Ideal for restoring power, fuel efficiency and reduced downtime

• Compatible with a wide range of John Deere agricultural and construction machines