Exhaust Valve Compatible With 1978-1982 John Deere 4640/4840 6619 10.1L 6-Cyl Diesel Tractor R63982

JOHN DEERE TRACTORS:
• John Deere 4640/4840 6619 10.1L Diesel (1978-1982)

JOHN DEERE COMBINES:
• John Deere 7720/8820 6619 10.1L Diesel (1979-1989)

JOHN DEERE SCRAPERS:
• John Deere 860B 6619 10.1L Diesel (1978-1986)


IMPORTANT:
EXHAUST valve for John Deere 6619 diesel engines (10.1L, 6-cylinder, turbocharged). Requires 6 exhaust valves per engine (2-valve-per-cylinder design). Do NOT confuse with intake valve R75690 — exhaust valves have a smaller head diameter than intake valves and are made of different high-temperature alloy. The 6619 engine is found in 4640/4840 tractors, 7720/8820 combines, and 860B scrapers.

When replacing exhaust valves on these high-hour vintage engines, always inspect valve guides for wear and valve seats for recession or pitting. Replace valve stem seals — old seals cause oil consumption and blue exhaust smoke. Check valve spring free length and replace springs that are out of spec. On turbocharged 6619 engines, exhaust valves see extreme thermal stress — check removed valves for heat cracking, face erosion, and tulip-shaped deformation. If one valve failed, inspect all remaining valves for early signs of the same failure. Measure valve protrusion (installed height) after seating. Adjust valve lash per service manual specs after reassembly.

⚠️ Exhaust valve only — for intake, order R75690.