Insurance companies that offer coverage for “rock damage” to combines often require claims be submitted within six weeks of the end of harvest. Of course you’ll check for damage to the usual suspects — feeder house drum, concave, threshing bars/rotor elements and straw chopper knives, but it is easy to overlook expensive collateral damage, including:
1. Feeder house conveyor chain. Check for bent or broken crossbars as well as damaged links in the actual chains.
2. Concave adjusting mechanism. The shock load of a rock, fence post or even a big wad of crop can break concave adjusting rods, linkages or brackets. The concave indicator in the cab might show movement up and down, but the concave itself moves unevenly because one side is not supported.
3. The housing that covers the threshing cylinder or rotor. A dent in that housing disturbs the smooth flow of material. Over time, the dent becomes a hole — but long after insurance has paid off the claim for the original damage.
4. The front of the upper sieve. Big chunks of rock can come off the concave and land hard enough on the sieve to buckle one or more louvers. Smaller rocks or field debris can shuffle back and forth on the sieve and bend louvers backward.
5. The straw chopper housing. Debris large enough to break off a chopper knife often also damages the sheet metal of the housing. Dents and small holes in the housing can erode and become larger holes. Cracks or torn metal can snag crop material and encourage the chopper to plug.
6. Straw chopper deflectors. If they’re simple curved vanes, check their front edges. Curled or ragged edges snag debris and increase the potential for plugging or uneven spreading of material. On powered spinners, look for broken/bent paddles or tines and check the adjustable shields and deflectors for dents, holes or missing parts that could encourage uneven spreading.
7. Lower clean grain auger/lower clean grain elevator. Small pieces of debris can wedge between the auger flighting or the auger housing and cause damage. This might not plug the auger, but it could create a dent that will erode more rapidly than the rest of the metal around it to create a hole.
Don’t forget rock (or fence post, or tree limb or field cultivator sweep) damage to corn heads and bean platforms. Be sure to check the following:
- Auger trough and auger flighting for bends or holes.
- Auger fingers.
- Auger bearing mounts and brackets. Any impact significant enough to bend the trough or flighting might have damaged the auger’s mounting points.
