Unitized Piston, 80mm Bore for John Deere Dozers & Crawler Loaders – RE34085

Part # RE34085

Fits Models At A Glance:

• John Deere Dozers — Blade Lift Cylinder:
  • 450G, 450H, 450J (Cylinder # AH211370, AHC15680), 450K
  • 550G, 550H, 550J, 550K, 550 P-Tier
  • 650G, 650H, 650J, 650K, 650 P-Tier
• John Deere Crawler Loaders:
  • 455G
  • 555G

Key Notes:

• Part Number: RE34085
• Weight: 2.20 lbs (1.00 kg)
• Bore Diameter: 80 mm
• Piston Dimensions: Installed width 40.74 mm, hole diameter 27.58 mm, counterbore 40 mm diameter × 20 mm deep
• Pressure Rating: Up to 5,000 PSI
• Type: Unitized piston — one-piece piston-and-seal assembly (steel body, non-metallic bearing, rubber loading ring, filled PTFE seal ring)
• Origin: Made in USA
• Cylinder Application: Blade lift cylinder (40 mm rod / 80 mm bore) across the 450–650 series dozers; fits 80 mm-bore loader cylinders on the 455G and 555G crawler loaders
• Fitment Note: This piston is sized to the bore listed above. Before ordering, match your cylinder's bore and existing piston dimensions against the specs — the same machine uses different pistons in different cylinders — note this 80 mm piston (40 mm counterbore × 27.58 mm hole) is NOT interchangeable with the 80 mm AH173410 piston (50 mm counterbore × 30.58 mm hole)

Common Use Case or Symptoms: Use when a cylinder is bypassing internally, drifting under load, or leaking past the piston — the unitized piston restores the internal seal without replacing the whole cylinder.

Why Choose Broken Tractor:

• ✅ Made in USA – precision-machined steel piston with the seal pre-installed
• ✅ Correct 80 mm Blade Lift Cylinder Fit – matched to the 450–650 series dozer lift cylinder bore
• ✅ Fast Shipping from a U.S.-Based Team – ready to ship from our U.S. warehouses