Part of the Case IH Repair Manuals.
Case IH SB521 through SB551 square balers, five variants in all, are the subject of this Case IH SB521–SB551 series service manual PDF: 660 pages of factory repair procedure filed under OEM number 47917637. Hydraulic schematics map the variable displacement pump, bale density circuit, and pickup lift circuit, while the tying coverage, close to half the book, carries knotter drive, needles, billhook, twine discs, and twister frame work from teardown through adjustment. PTO drive shaft, flywheel, gearbox, and clutch service opens the mechanical sections, with general specifications printed separately for each variant. Set your packer fork drive chain sag at 9 mm (3/8 in), and pull the needle yoke once vertical movement passes 0.8 mm (1/32 in). Dry hay doesn't wait while you hunt one adjustment figure. Searchable text and bookmarked sections put that number in front of you fast, so the baler ties again while the weather holds.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| Power Take-Off (PTO) | 42-148 | Power Take-Off (PTO) Drive Shaft, Flywheel, Gearbox, Clutches |
| Hydraulic Systems | 149-202 | Variable Displacement Pump, Bale Density Circuit, Pickup Lift Circuit, Frame Positioning Swinging |
| Product Feeding | 203-296 | Feeder Housing, Feeder Drive System, Pickup, Packer, Rotor |
| Pressing - Bale Formation | 297-334 | Plunger and Connecting Rod, Bale Chamber |
| Knotter Drive System | 335-346 | Knotter Control Drive Shaft, Bearing Removal, Bearing Installation, Shaft Replacement |
| Knotter Clutch and Brake | 347-362 | Brake Adjustment, Brake Pad Removal, Brake Pad Installation, Brake Disc Replacement, Knotter Clutch Dog |
| Knotter Trip Mechanism | 363-396 | Metering Wheel, Trip Arm, Drive Gear, Bale Counter, Trip Lever, Pivot Shaft |
| Needles | 397-442 | Needle Removal, Needle Installation, Needle Yoke, Needle Protection Latch, Needle Roller Replacement |
| Knotter Stack | 443-484 | Knotter Frame, Knife Arm, Billhook, Twine Disc, Twine Finger, Knotter Stack Assembly |
| Twine Guide System | 485-504 | Twine Tension Plates, Twine Holder, Twine Guide Adjustment, Worm Shaft and Gears |
| Knotter Frame | 505-560 | Knife Arm Adjustment, Billhook Replacement, Twine Disc Cleaners, Twine Finger Lever |
| Twister Frame | 561-660 | Hook and Shaft System, Shear Plate, Shuttle Bar, Shuttle Shaft, Twist Wrapper, Wire Guides |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Hitch pin distance from tractor PTO shaft | 355 mm (14 in) | p. 48 |
| Spring length for pivot arm and ratchet | 68 mm (2-11/16 in) | p. 50 |
| Maximum vertical movement of yoke | 0.8 mm (1/32 in) | p. 66 |
| Packer fork drive chain sag | 9 mm (3/8 in) | p. 208 |
| Rotor drive chain sag | 9 mm (3/8 in) | p. 209 |
| Sprocket teeth distance from feeder bulkhead | 29 - 31 mm (1–5/32 - 1–7/32 in) | p. 225 |
| pickup wheel flotation weight | 11 - 13 kg (24.3 - 28.7 lb) | p. 245 |
| Billhook cam spring length | 17 mm (0.67 in) | p. 479 |
| Knife arm to billhook clearance | 10 - 13 mm (0.394 - 0.512 in) | p. 479 |
| Billhook spring length | 17 mm (0.67 in) | p. 528 |
| Billhook groove pin size | 4 mm (0.16 in) | p. 529 |
| Twine holder extension (no twine) | 8 mm (0.31 in) | p. 537 |
