Case Ih 1020 Header Parts Diagram

Working with the Case IH 1020 Header Parts Diagram

The 1020 header was one of those workhorse units Case built in the early eighties before they consolidated a lot of their part numbering systems. If you are trying to source replacement parts for one now, the diagrams are not exactly easy to track down through normal retail channels. Most of them are held by Case IH dealers or buried in aftermarket reprint books. I have spent enough time digging through old parts binders at auctions and salvage yards to know where the useful information actually lives. The official parts diagrams for the 1020 flex head and the 1020 platform header break down into several major assemblies: the reel assembly, the cutterbar and gearbox, the elevator chain and sprockets, the header deck plates, the auger flighting, and the hydraulic lift cylinders with their valve blocks. Each diagram uses a two-part part number system. The first part is the base component number and the second identifies the specific configuration or material change. This matters because Case made subtle revisions throughout the production run without always updating the main diagram reference numbers cleanly. I ran into this exact problem when I was rebuilding the cutterbar gearbox on a 1983 1020. The diagram listed a particular seal kit as part number C83012, but the actual gearbox on the machine had been updated mid-production with a different seal profile. The older diagram part number would not fit. What I ended up doing was removing the gearbox, taking it apart, and measuring the seal bore with calipers before cross-referencing against a later revised diagram that showed the updated dimensions. Case dealer catalogs from 1986 and later included those revision notations. If you are working off an original diagram from the early eighties, assume some parts were superseded unless the diagram has a Revision B or C stamp on it.

Finding actual diagrams online is hit or miss. Case IH still maintains a dealer parts portal called CIPPS that has digital versions of most of these diagrams, but you need a dealer login to access it. The free version of their website shows part numbers for common items but rarely includes the actual exploded diagrams. Third-party sites like Agparts and TractorPartsEtc sometimes have scanned copies of the diagrams uploaded by dealers, but the scans are usually low resolution and hard to read for the small part numbers in the lower assemblies. The most reliable free route I have found is through the International Harvester and Case collector communities. There are a few Facebook groups and a couple of forums where members have scanned and cleaned up their own copies of the 1020 diagrams. These are usually done from original paper catalogs and tend to be readable. I have a personal collection of about six different 1020 header diagrams saved on my drive, pulled from various sources over the last ten years. The reel assembly diagram from a 1982 catalog is one of the clearest ones I have seen, and it shows the bearing part numbers for the reel shaft that most people struggle to identify. For people who just want to order parts without getting deep into the diagrams, there is a simpler workaround. Take a photo of the existing part with a ruler in the frame. Send that to a Case IH dealer parts counter along with the serial number of the header. The serial number is usually on a tag near the left side of the header wing where it connects to the main frame. They can pull up the electronic diagram for your specific serial range and verify the correct part number. This takes longer than looking it up yourself but it removes the guesswork around revisions and supersessions.

There are known trouble spots on the 1020 that come up repeatedly. The elevator chain tensioners wear out and the adjustment bolts strip if you force them. The diagram shows part number E40987 for the tensioner assembly, but many of those have been replaced with upgraded versions that have a different bolt thread pitch. The hydraulic lift cylinder rod seals on the left side lift arm are another common failure. The diagram lists a standard seal kit but the actual rod surface on these cylinders develops pitting over time that will destroy new seals within a season. The fix is either to polish the rods smooth with fine emery cloth or replace the cylinders entirely. It is cheaper to do the polishing if you catch it early. Another thing most people miss when looking at the 1020 header diagrams is the auger drag shoe assembly. The diagram shows a simple flat pad, but in practice those shoes wear into the deck plate over a few seasons and then start causing friction problems. The replacement shoes are available but the deck plate itself often needs skimming or replacement once the shoes have cut into it. I have seen operators put new shoes on worn plates and wonder why the auger binding never went away. The diagram does not call this out because it is a wear condition, not a parts replacement issue. Check the deck plate surface before ordering new drag shoes. If it is gouged more than a sixteenth of an inch, you need to address the plate first. If you are doing a full rebuild and want all the diagrams at once, there are reprint books available from publishing companies like Allis-Chalmers Collector Press and similar agricultural reprint publishers. They compile the diagrams into loose-leaf style booklets for specific model ranges. The 1020 is sometimes grouped with the 1040 and 1060 headers since they share a lot of design elements. Those reprints run somewhere between forty and eighty dollars depending on the publisher and usually include the engine and transmission diagrams for the combining head as well. They are worth it if you are doing serious restoration work because the scans are clean and the part numbers are legible.

The main limitation with any of these diagram sources is that they only show parts that were sold as replacements through the original distribution channels. Aftermarket modifications, welded repairs, and non-OEM substitutions that previous owners made are not documented anywhere in the diagrams. If you are looking at a used 1020 header and something looks wrong compared to the diagram, assume someone already modified it rather than assuming the diagram is wrong. This comes up more often than you would think on machines that have changed hands through several farm auctions over thirty years. What I usually recommend is starting with whatever diagram you can find, then physically verifying each part number against the actual machine before ordering anything expensive. The diagrams are generally accurate for the base configuration but the revision creep on Case parts from that era means you will save time and money by double-checking critical components rather than hoping the paper diagram matches what is actually bolted onto your header.