Production years
2004-2007
John Deere combine ยท 2004-2007
John Deere 9660 STS Combine
The John Deere 9660 STS is a Class 6 rotary combine from Deere's 60 Series. It is a well-regarded mid-to-large-acreage machine, known for the capacity and crop adaptability of its Single Tine Separation rotor.
Threshing system
STS single-rotor rotary separation
Engine
John Deere PowerTech 8.1 L six-cylinder diesel, 305 hp rated
Grain tank capacity
250 bu standard; 300 bu optional
John Deere 9660 STS specifications
| Production years | 2004-2007 |
|---|---|
| Threshing system | STS single-rotor rotary separation |
| Engine | John Deere PowerTech 8.1 L six-cylinder diesel, 305 hp rated |
| Grain tank capacity | 250 bu standard; 300 bu optional |
| Header compatibility | John Deere 600 Series platforms and corn heads; commonly 20-35 ft grain heads |
| Weight | Approx. 30,682 lb, corn configuration without header |
| Rotor | 29.6 in diameter by 123.3 in long |
| Fuel capacity | 250 gal |
What the 9660 STS is used for
The 9660 STS was designed for corn, soybeans, wheat, and other small grains on farms needing substantially more capacity than a conventional walker combine. Its rotary system is particularly suited to high-volume grain harvesting and changing crop conditions.
Today it remains a practical used combine for moderate-acreage farms and custom operators with access to Deere support. Owners commonly pair it with 25- to 35-foot grain platforms or six- to eight-row corn heads, according to crop and terrain.
Why the John Deere 9660 STS stands out
The 9660 STS is popular because it combines a proven 8.1 L Deere engine with the familiar STS rotary system, a 250-bushel standard tank, and broad header support. Its large installed base supports strong parts availability, although configuration and condition matter more than the decal year on an older machine.
Buying a used John Deere 9660 STS
Inspect the rotor elements, concaves, grates, feederhouse floor and chain, variable-speed drives, unloading system, and final drives. Verify engine and separator hours, look for grain loss or damage from past feederhouse plugs, and operate every hydraulic, electrical, and monitoring function; specifications and options should be confirmed against the serial number with TractorData.com and manufacturer records.
John Deere 9660 STS frequently asked questions
How much horsepower does a John Deere 9660 STS have?
It is commonly rated at 305 hp from a John Deere 8.1 L six-cylinder diesel.
How large is the 9660 STS grain tank?
The standard grain tank is 250 bushels, with a 300-bushel option.
Is the 9660 STS a rotary combine?
Yes. It uses Deere's STS single-rotor rotary threshing and separation system.
Specifications are commonly cited figures for general reference; exact figures vary by year and serial number, so confirm against TractorData.com and the machine's records. Values and prices of used combines vary by condition, hours, and region. Page updated Aug 4, 2026.