A breakdown in the middle of harvest costs far more than the part that failed. Every day a combine stands still is a day of crop left in the field, lost grain and pressure on the whole season. The good news is that most breakdowns start with wear you can spot in the workshop. This combine harvester maintenance checklist walks through the parts to inspect before harvest – with examples for New Holland Clayson 1545, 1550, 8060, 8070 and 8080 machines.
Why pre-season maintenance matters
Combines work hard for a few weeks a year and then sit for months. In storage, belts harden, bearings dry out, rust forms on sieves and knife sections, and rodents can damage wiring and filters. A full inspection before harvest lets you order replacement parts in good time, instead of waiting for delivery while the crop is ready.
Combine harvester maintenance checklist
1. Header and cutter bar
The cutter bar does the first job in the whole machine – if it cuts badly, everything behind it suffers. Check:
- Knife sections – chipped, blunt or missing sections tear the crop instead of cutting it.
- Knife fingers (guards) – bent or worn fingers stop the knife shearing cleanly. See the knife finger 379720 for 8060/8070/8080 combines.
- Knife clips – they hold the knife down against the fingers; worn clips cause gaps and poor cutting. See the knife clip 384357.
- Knife drive / wobble box – listen for knocking, check for oil leaks and play in the drive arm. Replacement: wobble box assembly 362353.
- Reel tines, reel bearings and the header auger fingers.
2. Threshing drum and concave
Inspect rasp bars for rounded edges and check the concave for bent wires or wear. Worn threshing parts leave grain in the ear and increase losses out the back of the machine. Check drum bearings for play and make sure the concave clearance adjustment moves freely.
3. Sieves and cleaning shoe
The sieves separate clean grain from chaff. Look for bent louvres, cracked frames, rust and blocked holes, and check that the adjustment mechanism moves the full range. A damaged sieve sends grain over the back or lets rubbish into the tank.
- Adjustable sieves – for example the adjustable sieve 427001-394856 for 8060/8070 combines.
- Sieve bars and supports – such as the sieve bar 481730-324715.
- Check the cleaning fan, fan casing and fan drive belt.
4. Straw walkers
Check walker crankshaft bearings, wooden or plastic bearing blocks and the walker steps for cracks. Worn bearings make the walkers knock and can break the crank.
5. Belts, pulleys and chains
Belts and drives are the most common cause of in-field stoppages. Replace any belt that is cracked, glazed, frayed or stretched, and check:
- Pulleys for worn grooves and wobbling – e.g. the idler pulley half 396863 and sheave pulley 395999.
- Belt guides – a damaged guide lets belts jump off. See the belt guide 411129.
- Chains and sprockets – hooked or sharp sprocket teeth wear new chains quickly; replace them together. See the sprocket 417785.
- Belt and chain tension, and tensioner springs.
6. Bearings and housings
Spin every accessible bearing by hand with the belts off. Roughness, noise, play or signs of heat mean replacement. Check bearing covers and flange plates for cracks and loose bolts, and grease all nipples according to the operator’s manual. Parts: bearing cover & flange plate range.
7. Engine, filters and cooling
Change the engine oil and filters, and inspect the air filter carefully – combines work in very dusty conditions. Clean the radiator and rotary screen, check coolant, fuel lines and the alternator belt. Air filter assemblies: filter assembly 448346 (1545) and filter assembly turbo 448346 (8080).
8. Grain handling and unloading
Check the elevator chains and paddles, grain tank augers and the unloading auger for wear and holes in the casings, which leak grain. Make sure the unloading auger swing works smoothly.
9. Hydraulics, electrics and safety
Look for leaking hoses and rams, test every light and warning signal, and make sure guards and shields are in place. Keep a fire extinguisher in the cab and blow chaff off hot engine areas regularly during harvest.
Quick pre-harvest checklist
| Area | What to check | Typical spare parts |
|---|---|---|
| Cutter bar | Knife sections, fingers, clips, knife drive | Knife fingers, knife clips, wobble box |
| Threshing | Rasp bars, concave, drum bearings | Rasp bars, concave, bearings |
| Cleaning | Sieves, fan, fan casing | Adjustable sieves, sieve bars |
| Drives | Belts, pulleys, chains, sprockets | Pulleys, belt guides, sprockets |
| Bearings | Play, noise, heat, greasing | Bearing covers & flange plates |
| Engine | Oil, filters, radiator, belts | Air filter assemblies |
Tips for ordering combine spare parts
- Use the part number. Original part numbers (for example 379720 or 427001) are the fastest way to get the right part.
- Confirm your model. Many parts differ between the 1545, 1550, 8060, 8070 and 8080, so always state the exact model.
- Order early. Make your list during winter servicing, not when the crop is ready.
- Send a photo if you cannot find a number – it helps us identify the part.
Frequently asked questions
When should I service my combine harvester?
The best time is straight after harvest, when wear is fresh in your mind, followed by a final check a few weeks before the next season starts.
Which combine parts wear out most often?
Parts that cut, rub or turn constantly – knife sections and fingers, belts, chains and sprockets, bearings, rasp bars and sieves – need checking and replacing most often.
Do you supply parts for older Clayson combines?
Yes. Our harvester spare parts range covers New Holland Clayson 1545, 1550, 8060, 8070 and 8080 combine harvesters.
Need combine harvester spare parts?
SMAZ Agri International UK supplies new replacement spare parts for New Holland Clayson combines. Browse all harvester spare parts, see our tractor and truck spare parts, or read our diesel generator sizing guide. Can’t find a part? Send us an enquiry with the part number or a photo and our team will help.