Most of the combine trouble we see at planting, and again at wheat, traces straight back to how the machine was parked in November. Chewed harnesses come from residue that fed mice all winter. Hard starts and fouled injectors come from fuel and DEF that sat from the last field to the first. Cracked belts come from cold storage on a machine nobody looked at. And the feederhouse chain or worn concave that stops you mid-wheat was already there in the fall, just never measured.
The order matters. Clean-out first, because you cannot inspect what you cannot see. Fuel, DEF, fluids and batteries second, so the machine is stable for the winter. Then the wear inspection with a tape and a feeler gauge, and last the software update and data backup. Do it soon after the last field, while the belt slip you felt under load is still fresh. Write every measurement and worn part down as you go; that sheet is what gets parts ordered while the shop is quiet.
Start where the grain actually settles: the grain tank floor and cross augers, the unloading auger sump, the rock trap, and the boots on the return and clean-grain elevators. Then go under the shoe and chaffer, around the rotor cage, and finish in the engine compartment, the exhaust shield, and the cooling package. Open every clean-out door and leave the sump and elevator doors open all winter. A sealed pocket of grain is a heated apartment for mice.
Blow out the engine bay and follow the wiring runs with the air wand, because chaff packs tightest where harnesses route along the frame. Pull the cab mats and clear under the seat too; half a granola bar feeds a mouse family as well as corn does.
Skip this and the bill shows up in spring. A chewed harness throws intermittent codes on the first day of wheat, and a technician can spend hours chasing a fault that comes and goes before touching the actual damage. The slower risk is worse: last year's chaff packed against the exhaust shield meets this year's hot exhaust on a dry June afternoon.
Fill the diesel tank most of the way before the combine goes in the shed, enough to keep condensation off the tank walls but with room for expansion. Add stabilizer and a biocide, then change the fuel filters now, not in April. A combine that sits all winter on a half tank grows water and algae, and your injectors should not be the first thing to meet either one. DEF can freeze without harm if the tank has headspace; what hurts it is age and heat. DEF that sat too long crystallizes and sets off quality faults and derates. If you cannot remember when you filled it, drain it and start fresh.
Change engine oil before storage, not after; used oil carries combustion acids that sit on the bearings all winter. While you are under there, check hydraulic, final drive, and gearcase levels and look for the wet spot on the floor that says a seal is going. Verify coolant freeze protection against the coldest night an Ohio or Indiana January can deliver, and check your operator's manual for the storage intervals your model calls for.
Last, the batteries. Put them on a maintainer or disconnect the ground. A dead battery in April is the most avoidable spring call there is.
Belts first, while you still remember which one squealed under load. Look for glazing, cracking in the grooves, and frayed edges, then check how much travel the tensioner has left. A belt at the end of its tensioner is one you are replacing anyway, so order it now rather than on a Saturday in wheat. Chains get a tape measure, not a glance. Check feederhouse conveyor chain stretch and slat wear, then the clean-grain and tailings elevator chains and their sprockets, since a hooked sprocket will eat a new chain by midseason. Lube everything before the combine sits.
Whichever head you ran last gets the hard look. On a corn head that means stalk rolls, deck plates, gathering chains, and gearbox oil. On a draper platform it is knife sections, guards, the knife drive, and belt tracking. Then open the separator: check concave and rotor element wear against the limits in your operator's manual, inspect chaffer and sieve louvers for bent slats, and grab the rotor and shoe drives to feel for play. Write the hours next to every component you measured so next fall has a baseline.
Finish with the electronics. Update display and machine software while you have connectivity in the shed, and back up this season's field data before anything gets cleared. If the display threw alerts through harvest, add them to your list.
Everything above is a walk-around. It finds the chaff pack behind the rotor cage, the belt with a glazed back, the drip under the hydro pump. What it will not find is bearing play inside the rotor, a feederhouse drum worn past its taper, or a concave clearance that drifted out of spec over a long season of corn. Those take gauges, panels off, and a few uninterrupted hours in a heated bay. A machine that ran hard and still sounds fine is exactly the one that hides a bearing until it lets go with beans ready and rain in the forecast.
The display has the same limit. A sensor flags what it can see, not what wears, so harvest alerts are a good first page for the conversation and a poor substitute for a tape measure.
If you would rather not spend a cold afternoon under the machine, or you want a second set of hands on the parts a walk-around cannot reach, our Off-Season Ag Inspection covers these same systems with the panels off and the gauges out. A certified technician measures what you eyeballed and writes up what is worn against what will make another season. Preventive work done in the off-season carries a discount, and one of our Customers, Dale French, put the case plainly: "There's no value to downtime."
Our shops across Indiana and Ohio fill up once combines come out of the field, and when planting equipment starts rolling in, the combine goes to the back of the line. Booking this winter leaves room to order and install without a deadline on anyone.
Either way, bring your measurements and worn-part list to our parts team. We will confirm the right belts, chains, concaves, and filters for your serial number and get them ordered ahead of harvest demand, so the machine goes back to the shed ready for spring and for next harvest.