Replace worn tines on the 55 series merger first–these components endure the most stress. Locate the tine retainer clips (OEM #84294764) directly beneath the rotor hub; corrosion here often spreads to adjacent fasteners. Use a magnetic screwdriver to retrieve loose bolts, as manual searches through crop residue waste time.
Inspect the bearing housing (OEM #87432010) weekly if operating in sandy fields. Seal failure here accelerates wear on the flanged bearing (OEM #34061807A1), leading to rotor misalignment. Apply high-temp grease sparingly, as excess attracts abrasive particles.
Tensioner pulleys (OEM #82379001) require torque checks every 50 hours. A click-type wrench set to 30 Nm ensures consistent belt pressure–over-tightening risks premature drive belt wear (OEM #83920288). Replace drive belts if fraying exceeds 1/4 inch, regardless of operational hours.
Gauge wheels (OEM #84921367) must rotate freely; seized bearings skew merger alignment. Clean debris from the wheel fork with compressed air, not water–moisture accelerates bearing corrosion. Stock replacement bearings (OEM #80457602) separately if frequent replacements are needed.
Verify hydraulic cylinder seals (OEM #3684109B2) annually. Leaks typically originate at rod ends; replace the entire seal kit, not individual O-rings. Use hydraulic oil ISO VG 46 with anti-wear additives to prolong seal life.
How to Locate Components for Your Hay Merger Model 55
Identify the tine arm assembly by examining the circular rotor section–this area includes fingers, brackets, and the pivot mechanism. Use the exploded view schematic found in the dealer’s repair manual (part #87400045) to match each bolt and spring with its respective position. Labels in the diagram correspond to the numbers stamped on actual pieces; cross-reference these before ordering replacements to avoid mismatched hardware.
Critical wear items you should inspect include:
- Urethane fingers (item #654-120) – check for cracks at the base
- Drive chains (#742-301) – measure elongation beyond 2% to determine replacement
- Gearbox seals (#510-223) – look for fluid leaks around input shaft
- Rotor bearings (#480-117) – spin test for grinding noises
For hydraulic system components, focus on the lift cylinder (#312-456). Disassemble the gland and piston rod–I-beam sections show excessive wear at 0.012″ clearance. Replace O-rings (#290-821) in sets even if only one shows degradation. Pressure test the system at 1,500 psi to confirm valve spool (#375-904) operation before reassembly.
Track down discontinued parts through aftermarket suppliers like TISCO or Certi-Pik, referencing the cross-reference chart below. For structural frame repairs, note the angle iron specifications match AISI 1018 steel, 3/16″ wall thickness. Weld repairs require low-hydrogen electrodes (AWS E7018) to prevent hydrogen embrittlement. Always torque wheel hub bolts (#104-567) to 120 ft-lbs in a star pattern sequence.
Locating Official Manufacturer Schematics for the 55 Series Hay Tool
Download verified schematics directly from New Holland’s primary portal by selecting “Support” followed by “Manuals & Literature.” Filter the search using the model prefix NH55, then choose the exploded-view PDF labeled “NH55 Mechanical Component Breakdown.” These files contain annotated illustrations of every sub-assembly, including tine arms, rotor hubs, drawbar pins, and hydraulic couplers, with OEM part numbers etched beside each element.
Regional dealers maintain a subscription to the MyNH platform that grants instant access to the same schematics in higher resolution and with interactive layers. Request login credentials from your nearest service center–most will email a link within two hours. Once logged in, navigate to the “Parts Lookup” tab and enter the serial number stamped on the main frame; the system will surface exact matches for every wear and replacement item.
Independent agricultural equipment databases such as AgriExpo and TractorHouse host downloadable PDF catalogs that mirror OEM schematics. Filter by make, series designation (55), and equipment category (hay conditioning implements) to retrieve a 12-page document detailing rotor blades, skid shoes, and tension springs alongside torque specifications. Ensure the file carries the manufacturer’s watermark to confirm authenticity.
Step-by-Step Assembly Guide Using the 55 Rotary Tedder Schematic
Begin by laying out all components on a flat, clean surface in the exact sequence shown on the technical blueprint. Verify each piece against the labeled sections–starting with the main frame (A1) and progressing through tine arms (B3-B8), pivot joints (C2), and springs (D1-D4). Missing or mismatched elements will disrupt alignment later, so cross-reference every item before proceeding.
Frame and Rotor Assembly
Attach the central rotor hub (A3) to the main beam (A1) using the specified bolts (M12x50). Ensure the hub rotates freely before securing fully–misalignment here causes uneven tine movement. Next, install the six tine arms (B3-B8) by sliding each into its respective slot on the hub, locking with cotter pins (E1). The schematic’s exploded view shows exact angular placement; deviations as small as 5° will affect field performance.
Connect the drive shaft (F2) to the PTO coupling, aligning splines precisely–force-fitting damages internal gears. Install retaining clips (G1) as indicated; loose connections lead to shaft detachment at operating speeds. For lateral stability, bolt the support brackets (H4) to the frame first, then adjust tension rods (I5) until the rotor clears obstacles by 10-15mm when manually rotated.
Tine and Ground Adjustment
Mount tine clusters (J7) onto arms, ensuring the curved ends face inward–reversed orientation reduces swath quality. Secure with locking nuts (K6) to manufacturer torque specs (25-30 Nm). For ground clearance, set the caster wheels (L9) to maintain 2-3cm height under tines; the schematic includes a table for soil conditions (loam: 2.5cm, clay: 2cm). Check all fasteners after 5 hours of use–they loosen rapidly under vibration.
Test rotation by engaging the PTO at 540 RPM. Listen for rhythmic tine contact–irregular sounds indicate misaligned arms or bent tines. Recheck pivot joints (C2) for grease; dry components wear 60% faster. Replace any corroded springs (D4) immediately–weak tension alters swath consistency. The blueprint’s callouts include troubleshooting arrows for common issues (e.g., “uneven tine spacing” = check B3/B5 alignment).
Key Wear Components for the 55 Series Hay Tool and Where to Find Them
Replace tine arms every 300–500 working hours, depending on soil abrasiveness–sandy conditions accelerate wear by up to 40%. The left and right arms (part codes 84059787, 84059788) sit beneath the rotor cage, secured by two M16 bolts each. Always inspect bearing seats for micro-cracks during replacement; deformed seats reduce arm service life by 25%. Torque bolts to 120 Nm in a cross pattern to prevent uneven stress distribution.
| Component | Part Number | Location | Typical Lifespan |
|---|---|---|---|
| Ground wheel assembly | 87330681 | Outboard axle stubs, behind rotor | 800–1,200 hrs |
| Rotor support bearing | 84044510 (kit of 2) | Central shaft, beneath gearbox | 600–900 hrs |
| Scraper blade set | 84059798A | Between rotor discs, above frame | 400–600 hrs |
Gearbox oil (SAE 80W-90, 1.4 L) degrades 15% faster when operating above 50°C–check viscosity monthly in hot climates. Drain via the 12 mm square plug on the bottom; refill through the dipstick tube until fluid reaches the upper mark 2 cm from the top. Contaminated oil (metal particles exceeding 0.5 mm) damages the helical gear pair (part 84044521) within 100 hours; replace the entire gearbox if scoring exceeds 0.8 mm on gear teeth.
Pivot pins for the pressure arms (part 84055310) corrode at 0.3 mm per year in high-humidity zones–coat with anti-seize compound during installation. Spacer bushings (part 84059812) on the tension spring shaft wear asymmetrically; measure inside diameter with a bore gauge: discard if clearance exceeds 0.2 mm. Keep spare grease nipples (part 274445) on hand–clogged fittings force lubricant past seals, doubling bearing failure rates.
Locating Faulty Components on the 55 Hay Turner Using Its Schematic
Begin by inspecting the tine arms for visible bending, cracks, or excessive wear–common failure points on the outer rows where stress concentrates. Compare measurements against the original specs: arms should flex no more than 15mm under load, and gaps between adjacent tines exceeding 3mm indicate deformation. Check pivot pins for rotational stiffness; if they require force to turn by hand, replace bushings before they seize completely. Look for uneven wear patterns on the ground wheels–flat spots or embedded debris point to misaligned axles or worn bearings.
Key Wear Indicators to Cross-Reference
- Tine plates: Replace if curled edges exceed 5mm or holes expand beyond 8mm diameter.
- Drive belts: Slippage signs include glazing on the contact surface or cracks deeper than 1.5mm.
- Safety shields: Rust-through or bent mounting tabs reduce coverage–critical for preventing debris ejection.
- Pressure springs: Test tension by compressing each to 70% length; weak springs hold less than 30kg force.
- Grease fittings: Missing plugs or dry residue indicate neglected lubrication–flush before corrosion spreads.
Use the schematic’s numbered callouts to track replacements, matching component labels to the manual’s torque specifications. Photograph suspect areas before disassembly to verify alignment issues during reassembly.