6125

John Deere 6125 / 12.5L Engine Rebuild Kits & Parts

At Heavy Duty Kits, we specialize in reliable, high-performance rebuild kits and engine parts for the John Deere 6125 / 12.5L PowerTech engines. Whether you’re working on early or late model engines, our rebuild kits are built to match or exceed OEM standards—ensuring your engine gets the longevity, efficiency, and durability it was designed for.

We carry a full line of John Deere 12.5L engine overhaul kits, including inframe kits, major rebuild kits, liner sealing kits, and more—perfect for agricultural, industrial, and construction equipment powered by this proven engine platform.

Engine Compatibility & Piston Identification

We offer tailored kits for all 6125 PowerTech variants from 1997 to 2007. Choose the correct kit based on your engine serial number (ESN) and piston part markings:

Early Models (1997–2001)

  • Engine Serial Number: Up to ESN 30,000
  • Piston IDs: RE66125 or RE503969
  • Applications: 6125A / 6125H PowerTech Engines

Late Models (2002–2007)

  • Engine Serial Number: After ESN 30,000
  • Piston IDs: RE505901, RE518748, RE524324
  • Applications: 6125A / 6125H PowerTech Engines

High Horsepower Late Models (2002–2007)

  • Engine Serial Number: After ESN 30,000
  • Piston IDs: RE515356, RE517209
  • Designed for higher output PowerTech versions

Our kits support multiple compression ratios—from 14.7:1 to 17:1—to meet the performance demands of both standard and high-horsepower applications.

Equipment Models

  • Combines: 9750 STS, 9860 STS
  • Excavators: 450C LC, 450LL
  • Farm Tractors: 9200, 9220, 9300, 9320, 9420, 9520, 9620, 9620T
  • Loaders: 744J, 824J, 844J
  • Engine Model: 6125AF001, 6125AFM75, 6125HDW01, 6125HDW02, 6125HDW03, 6125HH003, 6125HH006, 6125HRW01, 6125HRW02, 6125HRW05, 6125HRW07, 6125HRW13, 6125HRW14, 6125HRW15, 6125HRW16, 6125HRW17, 6125HT001, 6125SFM75, 6125HF070, 6125HRW18, 6125HZ007, 6125HZ008, 6125HZ009, 6125HZ013
  • Self Propelled Forage Harvesters: 7300, 7400, 7500, 7700, 7800

Why Choose Heavy Duty Kits for John Deere 6125 Parts?

  • Fast Nationwide Shipping
  • OEM-Equivalent Quality & Durability
  • Expert Support & Fitment Guidance
  • No Core Charges on Most Kits
  • Flexible Options: From Partial Repairs to Full Overhauls

Need Help or Not Sure Which Kit You Need?

Call us or use our online chat for instant assistance. Just provide your engine serial number (ESN), piston markings, or equipment model—we’ll handle the rest.