This severely worn vertical unloading auger (left) allowed as much grain to fall down the sides of the auger tube as it lifted, causing the auger to plug. Tier III and Tier IV diesel engines are very finicky about fuel cleanliness.
Tips to keep combines cruising all season long
If harvest has hit a rain delay or you’re caught up with the dryer and have a moment to read this, here are a few maintenance matters to keep your combine cruising during the final weeks of harvest:
Check feeder house conveyor chain tension. If conveyor chains get too slack, they can jump a tooth on one of their drive sprockets when a wad of crop goes in the feeder house. At minimum, running with the feeder-house conveyor chains "crooked" creates a lot of noise. At worst, it bends the crossbars and weakens the chain links; at very worst, they could break and feed the conveyor chain into the combine.
Even spring-loaded, self-adjusting feeder house conveyor chains can wear and stretch enough to jump sprockets. Keep the springs on self-adjusters at the proper tension. Remove half-links from the conveyor chains as needed to obtain that spring tension.
"It’s better to take time to cut links out of a conveyor chain and get it adjusted to the proper tension than let it run loose enough to jump the sprockets and maybe break the chain," says Jeff Gray, Claas Lexion product coordinator. "Digging a broken conveyor chain out of a combine is not fun."
Check the tension of the clean grain elevator conveyor chain. Inadequate chain tension allows paddles to flex back, reducing their carrying capacity and overloading the clean grain loading system.
Realize that adjusting the tension of the clean grain elevator chain could alter calibration values for yield monitors by changing the way grain strikes the mass flow sensor at the top of the clean grain elevator. Recalibrate yield monitors after chain maintenance.
Replace fuel filters. The tradition of changing fuel filters at the same time engine oil is changed might not keep engines operating at peak power. Modern engine oils, filters and engine designs can extend oil change intervals to as much as 250 hours, while Tier III- and Tier IV-certified diesel engines might need fresh fuel filters every 100 hours. Tier III and Tier IV engines are fussy about fuel cleanliness. Filling from portable fuel tanks can significantly shorten change intervals if stringent fuel cleanliness is not maintained.
Inspect engine air filters. Most manufacturers permit outer air filters to be blown clean with compressed air once or twice before replacement. Inner air filters should be replaced rather than cleaned, unless cleaning is specifically permitted by the manufacturer.
Inspect and clean cab air filter(s). There’s more benefit from a clean cab filter than mere operator comfort. A dirty cab filter can restrict airflow enough to overload and damage the electric motor that spins the cab fan.
While inspecting the cab filter, check to make sure the air conditioning system condensation drain tube drips water on the ground beneath the cab when the AC is running. If that tube is plugged, water will build up in the AC evaporator. Water in the evaporator housing can literally "freeze-up" the evaporator core or create enough humidity in the system that the windows fog over when the heater is on.
Clean the stone trap. If stone traps aren’t cleaned at least every three or four days, the dirt and crop debris that accumulates in them packs so tight that rocks bounce off and then into the combine. Cleaning stone traps daily keeps them full of lightly packed material that "absorbs" rocks and keeps them out of the machine.
"Exercise" the combine’s cleaning fan, concave and cylinder/rotor. If cleaning fan speed, concave setting and cylinder/rotor speed are run for days at a time without significant alteration, it’s beneficial to occasionally change those settings to keep their adjusting mechanisms free-moving.
Adjust fan and cylinder/rotor speeds up and down several hundred rpm. Completely open and close the concave before resetting it to the desired clearance. The same goes for variable speed feeder houses, adjustable deck plates on corn heads, and any other combine component that is adjustable from the cab.
- October 2013