For immediate maintenance on Ih’s 30-series hay cutter, locate the knife sections first–these involve the cutter bar segments and guards. The official manual lists 12 individual blade assemblies, each numbered 31–42, secured by 14-mm bolts. Replace any sections showing cracks wider than 1 mm; these compromise safety and efficiency. Check the wear plates (numbers 57–59) every 50 operating hours–grooves deeper than 0.2 inches require replacement to prevent uneven cutting.
Drive train components demand strict attention. The pitman arm assembly (ref. 63) connects to the crankshaft via two sealed bearings; grease these every 20 hours using NLGI #2 lithium grease. The connecting rod (ref. 65) must show no play exceeding 0.5 mm when shaken–excess movement indicates bearing failure. Inspect the knife head assembly (ref. 22) for bent fingers; straighten with a brass drift only–hammer strikes can weaken the material.
Hydraulic linkages should be examined for leaks at the piston seals (ref. 78). Use Loctite 545 sealing compound on threads if re-tightening to 35 ft-lbs doesn’t stop seepage. The slide adjustment mechanism (ref. 45) requires calibration–loosen the lock nut, set the gap between knife heads and guards to 0.006–0.012 inches, then re-tighten. For electrical issues trace wiring from the solenoid valve (ref. 91) to the fuse block–corrosion on terminals is common; clean with electrical contact cleaner before resorting to replacements.
IH Cutting Bar Mechanism: Component Breakdown & Schematic Reference
Locate the cutter bar assembly by identifying the angled gearbox housing on the right side–this connects directly to the main drive shaft via a splined coupling. Use a 17mm socket to remove the four bolts securing the gearbox to the frame, ensuring you support the bar to prevent damage to the curved blades when lowering it. Check the input shaft seal for wear; if grooves deeper than 0.5mm are visible, replace it with part #816347-C to prevent gear oil leakage.
The knife head section consists of 12 serrated segments, each held by two 8mm cap screws. Inspect the riveted wear plates under each segment; if gaps exceed 0.3mm between the plate and blade, remove the rivets with a drill bit no larger than 3.2mm and install new plates (#816401-A) using hardened steel rivets. Tighten cap screws in a crisscross pattern to 25 Nm, verifying smooth movement of the reciprocating bar by rotating the drive shaft manually.
Examine the pitman arm linkage, which translates rotational motion into lateral cutting action. If play exceeds 2mm, adjust the eccentric bearing (#816492-B) by loosening the castle nut and turning the adjustment bolt clockwise in 1/8-turn increments. Lubricate the needle bearings with lithium-based grease (NLGI 2) every 50 operating hours–over-greasing causes seal failure and attracts debris.
Drive System Troubleshooting
The main drive belt (#816523-D) should deflect no more than 15mm under 10kg of pressure. Replace if cracks appear or if the width reduces below 22mm. Align the belt pulleys by placing a straightedge across the faces–misalignment greater than 1mm causes premature wear. The tensioner spring (#816488-E) loses 8% of its force after 300 hours; replace if free length drops below 85mm.
Stabilizer skids (#816375-F) protect the cutter bar during operation. Adjust height so the skids bear 60% of the unit’s weight when lowered–check by slipping a 0.4mm feeler gauge under the blades. Replace skids if leading edges wear thinner than 3mm; improper adjustment accelerates blade chipping. Verify attachment bolts (M10, grade 8.8) torque to 45 Nm; use thread lock on the lower pair to prevent loosening from vibration.
For electrical components, test the PTO clutch coil (#816567-G) with a multimeter–resistance should read between 3.8 and 4.2 ohms at 20°C. Clean slip rings with dielectric grease if voltage drop exceeds 0.3V during engagement. The blade stop solenoid (#816582-H) requires 12.4V minimum to disengage; check wiring for chafing at frame rub points where 16-gauge wires pass through the tongue assembly.
Critical Elements of the Ih Hay Cutter Schematics
Begin servicing by locating the cutter bar assembly, marked in the upper left quadrant of the blueprint. This section houses the reciprocating blades and guards–components most prone to wear. Replace blades in pairs to maintain balance; mismatched sets cause vibration and premature gearbox failure. The guard spacing should not exceed 0.125 inches to prevent jamming.
The gearbox, positioned centrally, drives the entire cutting mechanism. Check the oil level quarterly; use SAE 80W-90 GL-4 lubricant. Failed seals are identifiable by oil leaks near the input shaft. Disassemble only if grinding noises persist–replacement gears must match the original 32-tooth count to ensure proper meshing.
Hydraulic and Structural Subsystems
The lift cylinder controls the deck height. Inspect hydraulic hoses for abrasions; cracked or bulging lines must be replaced immediately to avoid pressure loss. The piston rod should move smoothly–sticking indicates internal seal damage. Use OEM seal kits (part #49673-A) for rebuilds; generic alternatives compromise performance.
Focus on the wear plates beneath the cutter bar. These ¼-inch thick steel plates absorb impact and protect the frame. Measure thickness annually; replace if worn below 0.2 inches. The pivot pins securing the bar require greasing every 25 hours of operation–neglect leads to excessive play and misalignment.
The drive belt connects the PTO to the gearbox. A properly tensioned belt should deflect 0.5 inches under 10 lbs of pressure. Cracked belts often slip, causing uneven cutting. Replace belts proactively if cracks exceed 1/16 inch in depth. Verify pulley alignment using a straightedge–misalignment accelerates belt wear.
Inspect the skid shoes last. These adjustable runners set the cutting height and protect the bar. Replace if the contact surface shows grooves deeper than 0.1 inches. Secure fasteners with threadlocker to prevent loosening from vibration–stripped bolts require helicoil repairs to restore torque specifications (25 ft-lbs).
Step-by-Step Process to Locate Cutting Components and Protective Segments on Your Ih Hay Equipment
Begin by identifying the main cutting assembly along the underside of the implement’s frame. The primary sections are arranged in a staggered pattern, typically consisting of 12 to 18 alternating units. Each unit includes a serrated edge and a corresponding shield, secured by two bolts and washers. Mark the position of each before removal to ensure correct reinstallation.
Use a socket wrench (13mm) to loosen the fasteners holding the shields. These are often rusted or tightly secured, so applying penetrating oil 15 minutes prior simplifies removal. Turn counterclockwise while supporting the shield to prevent it from falling into debris. Store bolts and washers in labeled containers–group fasteners by their original position to avoid confusion.
| Component Type | Material | Replacement Interval | Identification Tip |
|---|---|---|---|
| Serrated edges | High-carbon steel | Every 40-60 hours | Look for sharp notches; dull or chipped edges signal wear |
| Protective shields | 10-gauge hardened plate | Annually or after severe impact | Check for cracks or bent edges near bolt holes |
| Fastening hardware | Grade-5 zinc-coated | Replace if stripped or corroded | Inspect threads under a light for deformities |
Inspect serrated edges for uneven wear–replace if notches are rounded or chipped beyond 2mm depth. The leading edge should exhibit a consistent razor-like profile; deviations reduce cutting efficiency. For shields, examine the curved section where debris impacts–dents or holes compromise protection. Use a straightedge for verification.
Clean mounting surfaces thoroughly before reinstallation. Remove rust with a wire brush, then apply grease to new hardware to prevent future corrosion. Align each shield’s curved lip with the corresponding serrated edge, ensuring a 1-2mm gap between them. Tighten bolts in a diagonal sequence to 25 ft-lbs to prevent warping.
Test functionality by manually rotating the drive shaft–each serrated edge should move freely without binding. Verify shields return to their original position after deflection. If misalignment occurs, adjust bolts incrementally until resistance disappears. Perform a final check at operating RPM to confirm vibration levels remain within normal ranges.
Key Components Prone to Failure in Ih Cutting Equipment and Maintenance Tips
Knife sections require replacement every 8-12 operating hours under normal conditions. Use hardened alloy blades (Rockwell 50-60) to extend service life by 30-40%. Match original equipment specifications: LH200 or equivalent tang angle prevents premature shearing at the rivet points. Clean cutting surfaces after each use to prevent sap buildup, which increases friction by up to 22% and accelerates wear.
Check pitman arms weekly for hairline fractures near the bearing journals–most failures occur within 200 hours of service. Replace with forged 4140 steel arms if original cast components show deformation. Lubricate needle bearings through the two grease fittings every 10 hours; water ingress causes 78% of bearing failures. Install protective boots if operating in wet conditions to extend bearing life by 45%.
Guard fingers crack along the leading edge after 150-200 field hours. Fabricate replacements from 3/16″ AR400 steel; plasma-cut patterns ensure proper clearance for the reciprocating mechanism. Verify finger spacing (0.060″ nominal) with feeler gauges–misalignment increases power consumption by 18% and reduces cut quality. Spot-weld repair cracks under 1″, but full replacement is necessary after three seasons for consistent performance.
Spring-loaded hold-down clips lose tension after 300-400 cycles. Measure free length: original OEM clips should be 2.75″ when uncompressed; replace any below 2.5″. Use music wire with zinc plating (ASTM A228) to maintain consistent pressure throughout the blade path. Adjust clip pressure to 12-15 lbs; excessive force causes premature drive train failure, while insufficient pressure allows blade lift and uneven cutting.
Inspect drive belts every 50 hours for sidewall cracking–most belts fail between 200-250 hours. Replace with Gates PowerBand BX55 (or equivalent) to handle the 3:1 speed ratio; incorrect profiles slip under load, generating heat that reduces belt life by 60%. Tension belts to 1/2″ deflection under 10 lb force; overtightening increases bearing load by 35%. Store spare belts indoors at 50-70°F; temperature extremes accelerate rubber degradation.