Heavy-Duty PTO Shaft for CASE IH Round Balers — CAT4 & CAT5
Direct-fit PTO shaft for CASE IH RB444–RB564. CAT4 (40–65 hp) & CAT5 (up to 100 hp), 1.375-6 spline, CV joint with friction clutch. Custom lengths available.
Heavy-Duty PTO Shaft Compatible with CASE IH RB Series Round Balers — CAT4 & CAT5, Friction Clutch Included
Product Title: PTO Shaft for CASE IH Round Balers | CAT4/CAT5 Constant Velocity Driveline with Friction Clutch

Product Overview & Compatibility
This agricultural transmission shaft is engineered as a direct-fit replacement for CASE IH round baler models requiring CAT4 or CAT5 constant velocity (CV) drivelines. It ships with a friction clutch pre-integrated, protecting your drivetrain from shock-load damage during bale formation cycles. Spline options cover the three most common CASE IH tractor outputs — 1.375‑6, 1.375‑21, and 1.750‑20 — so one SKU range serves the majority of RB series tractors without adapter kits.
Compatible baler models: RB444, RB454, RB454 Silage, RB454 Rotor Cutter, RB455A, RB464, RB554, RB564. The standard input shaft is 1.375‑6 spline; 1.375‑21 and 1.750‑20 configurations are available on request.
| Baler Model | PTO Shaft Size | PTO Required, hp (kW) |
|---|---|---|
| RB444 | CAT4 | 40 (30) |
| RB454 | CAT4 | 60 (45) |
| RB454 Silage | CAT4 | 65 (48) |
| RB454 Rotor Cutter | CAT5 | 100 (75) |
| RB455A | CAT4 | 40 (30) |
| RB464 | CAT5 | 70 (52) |
| RB554 | CAT5 | 70 (52) |
| RB564 | CAT5 | 80 (60) |
PTO Shaft for CASE IH Round Balers — Technical Specifications
The CV driveline is built around a cold-drawn seamless steel tube with a wall thickness of ≥4 mm (CAT4) or ≥5 mm (CAT5), giving it the torsional rigidity needed at full rated power without adding unnecessary rotating mass. Yokes are precision-forged from heat-treated alloy steel (C45 or equivalent) and shot-peened to relieve surface stress. The friction clutch is factory-set to the torque value recommended for each baler model, with an external adjustment ring that lets service technicians re-calibrate in the field without full disassembly.
| CV Type / Speed | Tractor Spline | Base Part Number |
|---|---|---|
| CAT3 / 540 rpm | 1.375‑6 | 71R4121UCW07000 |
| CAT4 / 540 rpm | 1.375‑6 | 71R6121UCW07000 |
| CAT4 / 1000 rpm | 1.375‑21 | 71R6121UCW08000 |
| CAT5 / 540 rpm | 1.375‑6 | 71R8121UCW07000 |
| CAT5 / 1000 rpm | 1.375‑21 | 71R8121UCW08000 |
- Tube material: Cold-drawn seamless steel, normalized
- Yoke material: Heat-treated alloy steel (C45 / 42CrMo), forged
- CV joint type: Constant velocity (Homokinetic), grease-sealed for life
- Clutch type: Multi-plate friction clutch, factory-set torque limit
- Rated speed: 540 rpm or 1,000 rpm (select at order)
- Spline options: 1.375‑6 (6-spline), 1.375‑21 (21-spline), 1.750‑20 (20-spline)
- Power range: 40 hp (30 kW) to 100 hp (75 kW), model-dependent
- Surface finish: Yellow zinc-chromate coating + UV-resistant plastic guard
- Certification: CE-marked; meets ISO 500 & EN 12965 safety standards
Key Features & Engineering Benefits of the PTO Shaft
▶ Constant Velocity Joint — No Vibration at Angle
Dual-pivot CV geometry maintains uniform rotational speed even when the baler tongue swings up to 25°. This directly reduces belt-wear and cam-lobe stress inside the RB series pickup unit — a common weak point on non-CV shafts running at high angles during headland turns.
▶ Integrated Friction Clutch — Drivetrain Overload Protection
The slip-clutch engages at a calibrated torque threshold, absorbing jam loads when the baler ingests a foreign object or a slug of wet silage. Testing on an RB464 running at 70 hp (52 kW) shows clutch slip response under 0.3 seconds, limiting peak gearbox input torque spikes to <120% of rated.
▶ Quick-Release Yoke — Under 60-Second Coupling
A spring-loaded locking collar on both tractor and implement ends allows one-hand attachment and release without tools. Operators switching between a round baler and a square baler during the same harvest season save measurable time across dozens of daily hook-ups.
▶ Heavy-Duty Cold-Drawn Tube — 40‑100 hp Rated
The drive tube is cold-drawn rather than hot-rolled, producing tighter dimensional tolerances (±0.2 mm OD) and a finer grain structure that improves fatigue life. Sliding section overlap is maintained at ≥150 mm at minimum working length to prevent pull-out under field extension cycles.
▶ Full-Length Safety Guard — CE & EN 12965 Compliant
A co-rotating plastic guard with funnel ends covers the entire shaft assembly including the CV joint. The guard is independently supported by bearing cups at each end so it stays stationary while the shaft rotates — standard requirement for CE-marked markets in the EU and UK.
▶ Corrosion-Resistant Finish — Field & Storage Durable
Yellow zinc-chromate electroplating on all steel components meets 240-hour salt-spray resistance per ISO 9227. This matters for balers stored outdoors over winter, where uncoated shafts often show surface rust by spring that migrates into the sliding joint and increases operating friction.

Installation & Maintenance Tips
- Verify shaft length before fitting. Measure compressed and extended working lengths with the baler at its lowest and highest hitch positions. The sliding overlap must stay above 150 mm at maximum extension; if it does not, order the next-longer shaft option.
- Grease the CV joint every 8 operating hours (or at the start of each baling season, whichever comes first). Use NLGI Grade 2 EP lithium-complex grease — do not substitute with general-purpose grease, as it lacks the extreme-pressure additive needed at the CV ball tracks.
- Check and adjust clutch torque annually. Clutch springs relax over time. Using a torque wrench on the adjustment ring, set the slip threshold to the value shown on the clutch plate label (usually 100‑120% of rated PTO torque). Re-check after the first 50 hours of the season.
- Inspect the guard after every use. A cracked or missing guard is a safety hazard and may fail compliance inspections. Replacement guards are available separately for the CAT4 and CAT5 sizes — keeping a spare on the shelf prevents downtime.
- Match spline profiles before ordering. The input shaft on the RB series is almost always 1.375‑6, but some 1000-rpm tractor models use 1.375‑21. Count the splines or check the tractor spec sheet before placing your order to avoid a fitment mismatch.
- Store with yoke ends horizontal. Hanging the shaft vertically for extended periods can displace the grease from the CV joint lower ball tracks. Lay it flat or use the provided storage bracket.
Frequently Asked Questions
Frequently Used Together
Customers pairing this PTO shaft with CASE IH round balers also order the following components to maintain a complete, matched drivetrain:
Universal Joints
Cross-and-bearing kits for CAT4/CAT5 yokes; 1,000-hr grease-nipple service intervals.
Agricultural Gearboxes
Right-angle bevel and inline ratio gearboxes for RB-series rotor and pickup drives.
OEM-spec replacement belts for RB454, RB464, RB554, and RB564 bale chambers.
Friction Clutch Plate Kits
Replacement multi-plate sets for CAT4 and CAT5 clutch housings; pre-set to OEM torque values.
PTO Shaft Safety Guards
Full-length co-rotating guards for CAT3‑5 shafts; CE and EN 12965 compliant, sold by size.
Agriculture sprockets and #50/60 roller chains for baler pickup and bale-wrap drives.
Ready to Order or Need a Custom Configuration?
Send us your baler model, tractor spline count, and required shaft length — we will confirm the correct part number and lead time within 24 hours. Custom lengths, non-standard spline combinations, and OEM-volume pricing are all available.
Also available in our PTO drivetrain range:
PTO Shaft for Square Balers |
PTO Shaft for Hay Mowers |
Agriculture Sprockets |
Agricultural Gearboxes


