Finding the Right Parts for Your New Holland 258
Looking at the right diagram saved me about three hours last September when I was trying to track down a worn tine arm on a customer's 258. The rake has been around since the late seventies, and New Holland went through a few schematic revisions before settling on the ones most shops actually use. The challenge is that there are several versions floating around online, and some of them mislabel the spring assembly or skip the drive chain tensioner entirely. You need to know which one you're looking at before you start ordering parts. The New Holland 258 Hay Rake Parts Diagram breaks down into a handful of main sub-assemblies: the reel frame, tine and arm assembly, gear box, wheel and axle, drive chain, and the main frame. Each of those has its own part numbering system. The serial number on the machine determines which revision your particular unit is on. New Holland started using a stamped serial plate near the hitch in the earlier models, then moved it to the side of the gear box housing later on. If you don't have the serial number handy, grab it before you do anything else. A lot of the confusion people run into comes from mixing parts between pre-1985 and post-1985 builds. The wheel hub configuration changes between those two points, and if you order the wrong one you end up with a fitment problem that costs more in returns than it saves in guesswork.
Where to Get an Official New Holland 258 Hay Rake Parts Diagram
The most reliable source is the New Holland parts catalog through an authorized dealer. You can get it in book form with actual exploded views, or as a digital file. The digital version is easier to search but sometimes the image quality is poor enough that small fasteners blur together. I keep a printed copy for reference and use the digital one when I need to look up a specific part number quickly. There are also third-party sites that offer scanned copies, but the detail varies wildly. Some are clear enough to read part numbers, others are so degraded you're just guessing at the ink blobs. The dealer route costs money but it's reliable. The free internet versions are worth browsing but don't rely on them exclusively when you're actually ordering parts. When I was working through a rebuild on my own 258 last year, I discovered that the official diagram listed a specific spring part number for the tine return springs, but the physical springs on my machine were a different length than what the diagram showed. New Holland had made an engineering change mid-production that wasn't reflected in the diagram I was using. The workaround was simple: measure the old spring and cross-reference with the superseded part number list that New Holland publishes separately. The supersession notes are usually buried in the back of the full catalog, but they're there. If you're working on a machine with a serial number past the midpoint of production, check the supersession sheet first before ordering anything. It will save you a trip to the counter. The gear box is where most people spend the most time and money. The diagram shows the input shaft, output shaft, gears, bearings, seals, and the lubrication system. The standard fill is SAE 80W-90 gear oil, and the capacity is roughly 1.5 quarts. People often overfill it, which causes leaks through the seals because the oil expands when it heats up during operation. Leave a quarter inch of space at the fill plug. The breathers on these gear boxes are simple rubber plugs, and when they get clogged with dust and chaff the pressure buildup forces oil out past the seals. I've seen that more times than I can count. Clean the breather every season, and replace it if it's cracked or hardened. The cost is about two dollars and it prevents a hundred dollar seal replacement job.
The tine arms are wear items. They bend. They crack at the weld points where the arm meets the reel frame. When you're looking at the parts diagram, pay attention to the part number for the tine arm assembly, not just the individual tine. A lot of aftermarket suppliers sell just the tine, but the real issue is usually the arm itself. I had a customer who kept replacing tines on the same arm and wondering why the problem came back. The arm had a hairline crack that wasn't visible until I cleaned off the grease and held it up to the light. A magnaflux check would have caught it faster, but I didn't have that equipment on site. Sometimes the obvious solution is to just buy a new arm assembly instead of patching the old one. The part runs around eighty dollars from a dealer, and it's done forever. Trying to weld and re-tine the old arm costs about the same in labor and rarely holds up as well. The drive chain system is straightforward but often neglected. The diagram shows the chain, tensioner, sprockets, and the guard. The chain needs to have about half an inch of slack measured at the midpoint between sprockets. Too tight and you wear out the bearings in the gear box and the wheel hubs. Too loose and it jumps teeth or falls off completely. I learned that the hard way after a season of cutting hay. The chain was so loose it skipped a tooth on the output sprocket, which threw the timing of the reel. The tines hit the ground instead of sweeping the windrow. That stopped the machine in a hurry and bent three tine arms before I noticed it. After that, I check the chain tension before every use during harvest season. It takes about thirty seconds. One thing the diagram doesn't make obvious is how the wheel bearing preload works. The outer bearing is held in place by a castle nut and cotter pin. The correct adjustment is snug but not tight. If you preload it too much, the bearings overheat and fail within a season. If you leave it too loose, the wheel wobbles and wears out the hub. The sweet spot is when the wheel spins freely with no side-to-side play. It sounds generic but it's the correct procedure. If you want a more precise method, torque the nut to twenty-five foot-pounds while rotating the wheel, then back it off to the next cotter pin hole. That's the factory recommendation and it works.
Get the Full Details
If you're doing a full rebuild and want to order everything at once, here's a rough parts list based on what I typically pull from the diagram for a complete overhaul: gear box seal kit, both wheel bearing kits, tine arm assemblies (usually four to six depending on damage), return springs, drive chain, sprockets if worn, and the tine guards. The total runs anywhere from four hundred to nine hundred dollars depending on how much you replace versus how much you refurbish. The gears themselves rarely need replacing unless the unit has been run dry or with contaminated oil. Most failures are seals and bearings. Start there. The diagram is a tool, not a bible. Real-world machines don't always match the schematic exactly. Serial numbers, regional variants, and mid-production changes mean you should always verify what you're ordering against the actual machine. A five-minute measurement and comparison before placing an order prevents a lot of frustration. I keep a small notebook with serial numbers and the corresponding revision notes for each 258 I work on. It's not glamorous but it stops the guesswork. When you're standing in a field with a broken rake and the sun is going down, having that information saved means you either have the right part in your truck or you know exactly what to order before the dealer closes.
