Production years
2008-2011
John Deere combine ยท 2008-2011
John Deere 9770 STS Combine
The John Deere 9770 STS is a Class 7 rotary combine from the late STS era. It is a high-capacity, widely documented machine with a 360 hp 9.0 L Deere engine and a 300-bushel grain tank.
Threshing system
STS single-rotor rotary separation
Engine
John Deere PowerTech 9.0 L six-cylinder diesel, 360 hp rated
Grain tank capacity
300 bu
John Deere 9770 STS specifications
| Production years | 2008-2011 |
|---|---|
| Threshing system | STS single-rotor rotary separation |
| Engine | John Deere PowerTech 9.0 L six-cylinder diesel, 360 hp rated |
| Grain tank capacity | 300 bu |
| Header compatibility | John Deere 600 Series platforms and corn heads; commonly 30-40 ft grain heads |
| Weight | Approx. 37,236 lb, corn configuration without header |
| Rotor | 29.6 in diameter by 123.3 in long |
| Fuel capacity | 305 gal |
What the 9770 STS is used for
The 9770 STS was built for high-output corn, soybean, wheat, and small-grain harvesting on larger farms and custom crews. Its power and large tank let it carry wider platforms and larger corn heads than the smaller STS models.
It is still valued where an older, productive Class 7 combine fits the farm's acreage and labor plan. Buyers often use it with 30- to 40-foot platforms and eight- or twelve-row corn heads, provided field conditions and grain-cart capacity can keep pace.
Why the John Deere 9770 STS stands out
The 9770 STS is notable for combining 360 rated horsepower, a 300-bushel tank, and Deere's established STS rotor in a machine that was extremely common in North American grain country. Its popularity supports parts and service access, while its capacity remains useful for many operations despite its age.
Buying a used John Deere 9770 STS
Check engine and separator hours separately, then inspect the rotor, concaves, separator grates, feederhouse, clean-grain elevator, unloading auger, hydrostatic drive, and final drives. Confirm that the header and feederhouse options match, test the yield-monitor and electronic controls, and inspect for bearing heat damage, leaks, or deferred maintenance; verify specifications by serial number with TractorData.com and manufacturer records.
John Deere 9770 STS frequently asked questions
How much horsepower does a John Deere 9770 STS have?
It has a commonly cited rated output of 360 hp from a John Deere 9.0 L engine.
What is the grain tank capacity of a 9770 STS?
The 9770 STS has a 300-bushel grain tank.
Is the 9770 STS a good used combine?
It can be an excellent high-capacity used combine when its rotor, feederhouse, driveline, electronics, and service history check out.
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.