1. Cutting and Feeding System:

• Cutterbar Sections (Knife Sections): The individual triangular blades on the cutterbar that reciprocate to cut the crop. They dull and break easily from contact with the ground, rocks, and tough stalks.
• Guards (Finger Guards): The stationary “fingers” that hold the crop while the sections cut against them. They can wear out, bend, or break.
• Sickle Bolts: Bolts that hold the sections to the knife bar. They shear or break due to the high stress of cutting.
• Feeding Auger Flights: The spiral paddles on the header auger that gather the cut crop. The edges wear down, and flights can get bent.
• Gatherer Belts / Pickup Belts (on Pickup Heads): Belts with tines that lift the swathed crop. Belts can stretch, break, or lose tines.

2. Threshing and Separation System:

• Rasp Bars (Cylinder / Rotor Bars): The bars on the rotating cylinder or rotor that thresh the grain from the straw. They undergo extreme abrasion and wear down over time.
• Concaves: The curved, stationary grates beneath the cylinder/rotor. They are highly susceptible to wear and can crack or break.
• Walker Shoes (on Conventional Combines): The shoes on the straw walkers that help separate grain. The slats and surfaces wear out.
• Separation Grates / Sieves (in Rotor Combines): Grates in the rotor cage that allow grain to pass through. They wear and can be damaged by foreign objects.
• Threshing / Separation Belts: Belts that drive the cylinder/rotor. They are under high load and can stretch, fray, or break.

3. Grain Handling System:

• Elevator Chains and Flights (Auger Fingers): The chains and rubber/plastic paddles (flights) in the grain tank elevator. Chains stretch and flights wear out or break from constant use.
• Grain Tank Auger Flights: The spiral flights of the unloading auger. They wear thin, especially at the tips.
• Grain Pan Crank Arms (on some models): Components that drive the oscillating grain pan. Bearings fail, and arms can fatigue.

4. Straw Handling System:

• Straw Chopper Knives / Flails: The rotating knives or flails that chop the straw. They dull quickly, break upon hitting rocks, and their mounting hardware can loosen.
• Spreaders: The paddles that spread the chaff and straw. They wear down and can break.

5. Hydraulic and Drive Systems:

• Hydraulic Hoses and Fittings: Hoses can chafe, burst, and fittings can leak due to high pressure and constant movement.
• Drive Belts: Numerous belts power various components like the rotor, fan, and augers. They slip, glaze, crack, and break.
• Chains and Sprockets: Used in drives and feeders, they stretch, wear, and can break.
• Bearings: Bearings are found throughout the machine (rollers, augers, rotors). They fail due to heat, contamination, and load, leading to seizing or play.

6. General and Electrical:

• Tires and Tracks: Prone to punctures, sidewall damage, and general wear.
• Filters (Air, Fuel, Hydraulic, Oil): Require regular replacement as they become clogged.
• Light Bulbs and Fuses: Simple but essential electrical components that frequently fail.
• Sensors: Yield monitors, speed sensors, and level sensors can be damaged by vibration, dust, and impact.