John Deere 7720 Combine Parts
The John Deere 7720 combine, manufactured from 1980 to 1984, was a popular choice for farmers needing a reliable and capable machine. Powered by a John Deere diesel engine producing around 175 HP, it offered header widths up to 30 feet, allowing for efficient harvesting of various crops. Its conventional separator design provided dependable performance and made it a respected workhorse in the field.
The John Deere 7720 combine was introduced in 1980 as part of the '20 Series', replacing older models and offering improvements in capacity and operator comfort. It was produced until 1984. The 7720 is powered by a John Deere 6.6L (404 cu in) 6-cylinder diesel engine, delivering approximately 175 horsepower. It utilizes a conventional threshing system with a 43-inch wide cylinder and a walker separation system. The grain tank holds approximately 155 bushels, and the unloading auger can empty the tank at a rate of around 45-50 bushels per minute. Available header widths ranged from 13 to 30 feet, accommodating different row spacings and crop types. Chopper and spreader options were available to manage residue. The cab featured improved ergonomics compared to previous models, offering a more comfortable operating environment. The 7720 is particularly well-suited for harvesting wheat, soybeans, and corn, providing reliable performance in a range of field conditions.
Specifications
| Engine | John Deere 6.6L 175 HP Diesel |
|---|---|
| Separator Type | Conventional - 43-inch Cylinder |
| Grain Tank | 155 bushels |
| Unloading Rate | 45-50 bu/min |
| Header Widths | 13-30 ft |
| Fuel Capacity | 95 gallons |
| Weight | 17,500 lbs |
| Years Produced | 1980-1984 |
Maintenance Tips
- Concave Adjustment: Regularly check and adjust the concave clearance to ensure proper threshing and minimize grain damage. Consult your operator's manual for recommended settings based on the crop being harvested.
- Belt and Chain Tension: Inspect all belts and chains for proper tension and wear. Adjust tensioners as needed to prevent slippage and premature failure. Lubricate chains regularly.
- Sieve and Chaffer Cleaning: Clean the sieves and chaffer frequently to remove debris and ensure proper grain separation. Clogged sieves can lead to grain loss and reduced efficiency.
- Bearing Greasing: Grease all bearings according to the manufacturer's recommended schedule. Proper lubrication is crucial for preventing bearing failure and extending the life of your combine.
History & Background
The John Deere 7720 was introduced in 1980 as part of the '20 Series' combines, representing a significant upgrade in harvesting technology at the time. It replaced earlier models and offered increased capacity and improved operator comfort. The 7720 became known for its reliability and efficiency, contributing to its lasting impact on the agricultural landscape.
Frequently Asked Questions
What engine is in the John Deere 7720?
The John Deere 7720 is equipped with a John Deere 6.6L (404 cu in) 6-cylinder diesel engine, producing approximately 175 horsepower.
What is the grain tank capacity on a 7720?
The grain tank capacity on a John Deere 7720 is approximately 155 bushels, with an unloading rate of around 45-50 bushels per minute.
What type of separator does the 7720 have?
The John Deere 7720 utilizes a conventional threshing system with a 43-inch wide cylinder and straw walkers for separation.
What are common parts needed for the 7720?
Common wear parts for the John Deere 7720 include concaves, rasp bars, belts, chains, bearings, auger fingers, and sickle sections.

U12331 - Durometer 75 (4/Pack) .139" Thickness O-Ring; 2.734" ID X 3.012" OD
SKU: U12331
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R71732 - Durometer 75 (5/Pack) O-Ring; 1.234" ID X 1.512" OD X .139" Thick
SKU: R71732
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P46051 - Durometer 70 (10/Pack) .103" Thick O-Ring; .424" ID X .630" OD
SKU: P46051
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M40514 - External; 10/Pack Snap Ring
SKU: M40514
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H81330 - Seal Isolator
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B3690R - Durometer 75 (5/Pack) O-Ring; 1.859" ID X 2.137" OD X .139" Thick
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H77010 - Shoe Grain Supply Augers Belt
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