John Deere 8120 Tractor Parts
8120 parts and accessories
The John Deere 8120 tractor, manufactured from 2003 to 2006, is a workhorse known for its power and reliability on the farm. Equipped with a robust John Deere PowerTech 8.1L diesel engine producing around 200 horsepower, the 8120 offers a PTO horsepower of approximately 175. Its blend of power, versatility, and operator comfort made it a popular choice for row crop farming and heavy tillage operations.
The John Deere 8120 was introduced as part of the 8020 series, replacing the earlier 8010 models and offering improvements in performance and technology. Production spanned from 2003 to 2006. At its heart lies a John Deere PowerTech 8.1L 6-cylinder diesel engine, producing approximately 200 horsepower (149 kW) at the flywheel. The engine features a displacement of 496 cubic inches (8.1 liters) and is turbocharged for enhanced power and efficiency. Transmission options include a 16-speed PowerShift transmission providing smooth gear changes under load. The independent PTO delivers around 175 horsepower (130 kW) and offers both 540 and 1000 RPM speeds for versatility. The hydraulic system provides a flow rate of approximately 30 GPM (113.6 L/min), and is often configured with 3-4 remote valves. It features a Category III 3-point hitch with a lift capacity of around 9,921 lbs (4500 kg). The 8120 found common application in row crop operations like planting and cultivating corn and soybeans, as well as in hay production and heavy tillage tasks. Its heavier frame and powerful engine differentiate it from smaller models in the John Deere lineup, making it well-suited for demanding tasks.
Specifications
| Engine | John Deere PowerTech 8.1L 200 HP Diesel |
|---|---|
| PTO HP | 175 HP @ 540/1000 RPM |
| Transmission | PowerShift 16-Speed |
| Hydraulics | 30 GPM, 3-4 remotes |
| 3-Point Hitch | Category III, 9,921 lbs |
| Fuel Capacity | 125 gallons |
| Weight | 19,321 lbs |
| Years Produced | 2003-2006 |
Maintenance Tips
- Engine Oil & Filter: Change your engine oil and filter every 250-300 hours of operation, using the recommended John Deere oil specification. Regularly check the oil level to prevent engine damage.
- Hydraulic System: Inspect hydraulic hoses and fittings for leaks regularly. Change hydraulic fluid and filters according to the manufacturer's recommendations (typically every 1000-1200 hours) to maintain optimal performance.
- Fuel System: Use clean, high-quality diesel fuel. Replace fuel filters at recommended intervals to prevent fuel system contamination and ensure proper engine operation. Consider using a fuel additive during winter months to prevent gelling.
- Seasonal Storage: Before storing the tractor for an extended period, stabilize the fuel, change the engine oil and filters, grease all fittings, and disconnect the battery. Store the tractor in a dry, sheltered location.
History & Background
The John Deere 8120 was part of the 8020 series launched in 2003, representing an evolution in tractor design and performance. This model built upon the success of previous John Deere tractors, incorporating technological advancements and improved operator comfort. The 8120 played a significant role in modern agriculture, offering farmers a powerful and reliable solution for a wide range of tasks.
Frequently Asked Questions
What engine is in the John Deere 8120?
The John Deere 8120 is equipped with a John Deere PowerTech 8.1L 6-cylinder turbocharged diesel engine producing approximately 200 horsepower.
What is the PTO horsepower on a 8120?
The John Deere 8120 has a PTO horsepower rating of approximately 175 HP and offers both 540 and 1000 RPM PTO speeds.
What oil filter fits the 8120?
The John Deere 8120 typically uses a John Deere oil filter part number RE504836. Cross-references include Baldwin BD7153 and Fleetguard LF9009.
What are common parts needed for the 8120?
Common wear parts for the John Deere 8120 include engine oil filters, fuel filters, hydraulic filters, air filters, fan belts, hydraulic cylinder seal kits, steering components (tie rod ends), clutch discs (if applicable) and PTO shaft components.

RE206146 - ILS Steering Cyl Piston Seal
SKU: RE206146
32 in stock

RE204264 - Transmission Oil Pressure Sensor
SKU: RE204264
151 in stock

RE193357 - Control Arm Seal
SKU: RE193357
55 in stock

RE154869 - Front Axle Seal
SKU: RE154869
142 in stock

RE14439 - Oil Seal
SKU: RE14439
120 in stock

R95119 - Steering Cylinder Pin; MFWD; Seal
SKU: R95119
266 in stock

R87047 - Durometer 70 O-Ring; 13.490" ID X 13.768" OD X .139" Thickness
SKU: R87047
135 in stock

R82908 - Separator Plate
SKU: R82908
193 in stock

R73635 - MFWD Steering Motor Rear Pivot Pin
SKU: R73635
60 in stock

R72090 - Bearing; MFWD Cup
SKU: R72090
547 in stock

R557917 - ILS Upper Pivot Shaft
SKU: R557917
16 in stock

R542099 - ILS Special Locking Flange Nut
SKU: R542099
74 in stock

R537928 - Independent Link Suspension Cylinder Pin
SKU: R537928
39 in stock

R30398 - Thrust (Spindle) Washer
SKU: R30398
326 in stock

R290015 - MFWD Pinion Carrier Oil Plug
SKU: R290015
50 in stock

R237713 - Bevel; MFWD Gear
SKU: R237713
228 in stock

R237709 - Bevel Pinion; MFWD Gear
SKU: R237709
109 in stock

R179849 - Bearing Cup
SKU: R179849
149 in stock

R159931 - MFWD Planetary Ring Gear Hub
SKU: R159931
10 in stock

R134224 - MFWD Front Pivot Support O-Ring
SKU: R134224
75 in stock

R133564 - Rod End Pin; Steering Cylinder
SKU: R133564
21 in stock

R131511 - Differential Bevel Pinion Shaft
SKU: R131511
84 in stock

R130069 - MFWD Axle Housing Bushing
SKU: R130069
201 in stock

R125974 - Front Axle Support Bushing
SKU: R125974
50 in stock
