Bareco Wide Angle CV Drivelines: When a Standard PTO Shaft Won't Do the Job

Last updated June 2026

A standard PTO drive shaft works well when the tractor and implement are running roughly in line. Push the angle too far — tight turning circles, front-mounted attachments, side-discharge implements — and the universal joints start causing problems: vibration, power pulses through the driveline, premature joint wear, and in severe cases, shaft failure. A constant velocity (CV) driveline solves this. It delivers smooth, constant output regardless of the operating angle, up to 80 degrees of articulation at the CV end.

Bareco 9988 Series CV drivelines are rated from 35HP to 200HP and are available in standard wide-angle (one CV end) and wide-angle-both-ends configurations. This guide covers when you need one, how they work, and how to choose the right variant.

View the Bareco CV driveline range →

Why Standard PTO Shafts Have an Angle Limit

A standard PTO shaft uses universal joints (U-joints) at each end. U-joints transmit torque through an angle — but they do so with a velocity fluctuation: the output shaft speeds up and slows down twice per revolution at any angle other than zero. At small angles (up to around 15–20 degrees) this fluctuation is negligible. At large angles — the kind you encounter when a tractor turns sharply with a front-mounted implement, or when a side-discharge machine operates at a steep offset — the velocity pulses become significant. The result is vibration, stress on the implement gearbox, accelerated joint wear, and reduced component life.

A constant velocity joint eliminates this. The CV joint design ensures that the output shaft rotates at exactly the same velocity as the input shaft regardless of the angle, up to the joint's rated maximum. Smooth power delivery at tight angles is the result.

When You Need a CV Driveline

The main applications for wide-angle CV drivelines on Australian farms:

• Front-end loader implements — front-mounted mowers, brooms and brushes where the implement operates at a large angle to the tractor PTO
• Slashers on tight turning circles — where the tractor regularly turns sharply while the implement is engaged
• Towed implements on headland turns — where the implement angle to the tractor exceeds the standard PTO shaft's practical limit during turning
• Side-discharge and offset implements — any application where the implement input is offset from the tractor PTO centreline

If you are running a standard PTO shaft and experiencing vibration, rapid U-joint wear, or gearbox damage that can't be explained by overloading, steep operating angles are a likely cause. A CV driveline addresses the root problem rather than replacing joints repeatedly.

The 80-Degree Limit

Bareco 9988 Series CV drivelines are rated to a maximum of 80 degrees of articulation at the CV end. This is significantly wider than a standard U-joint (practical limit approximately 20 degrees), but it is still a hard limit. Exceeding 80 degrees causes CV joint failure and is not covered under warranty.

A turning limiter on the implement drawbar is recommended to prevent the angle from being exceeded during tight manoeuvres. If your application regularly approaches the 80-degree limit, confirm the geometry before ordering.

Standard Wide-Angle vs Wide-Angle-Both-Ends

Standard wide-angle (WB and WW prefix): The CV joint is at the tractor end only. The implement end uses a standard quick-release yoke. This suits most applications where the angle at the implement end is small and the angle at the tractor end (during turning) is the issue.

Wide-angle both ends (WWB prefix): CV joints at both the tractor end and the implement end. Used where the implement also operates at a significant angle — for example, a side-discharge mower where the implement input shaft is angled relative to the driveline both when turning and when running in a straight line. The WWB6150 covers 64HP at 540 RPM with this configuration.

Full Variant Range

Most variants use 1-3/8" x 6-spline quick-release yokes at both ends — the standard connection on most Australian tractors and implements. The W671306134 and W67130620 are high-HP variants with a 1-3/4" spline on one end, used on larger tractors with 1-3/4" PTO outputs. A patented lever-release guard is included with all variants.

Choosing the Right Variant

Step 1 — HP rating: Match the shaft's HP rating to your tractor's PTO output at the relevant RPM (540 or 1000). Always rate to the tractor's full PTO output, not just the load you expect to run — shock loads during engagement or implement stall can briefly exceed normal running load.

Step 2 — Shaft length: Measure the distance from the tractor PTO to the implement input in the working position. The shaft must not be fully collapsed or fully extended in normal operation — allow 20–30mm of compression travel from the working position to the collapsed length. Order the variant whose closed-to-open range brackets your required working length with adequate travel on both ends.

Step 3 — Wide-angle one end or both ends: For most applications (tight turning circles, front-mounted implements) the standard wide-angle shaft (one CV end) is the correct choice. If the implement input is also offset or angled during operation, consider the WWB wide-angle-both-ends option.

Step 4 — Spline specification: Most tractors up to around 100HP use 1-3/8" PTO outputs. Larger tractors from approximately 100HP upward often use 1-3/4" outputs. Confirm your tractor's PTO spline diameter and count before ordering the high-HP variants.

Custom yoke combinations and slip clutch additions are available on request. Call 1300 027 886 if your application requires a non-standard configuration.

View the Bareco CV driveline range →  |  PTO shafts guide →  |  Full Bareco range →

Frequently Asked Questions

What is the difference between a CV driveline and a standard PTO shaft?

A standard PTO shaft uses universal joints that cause velocity fluctuation at steep angles — resulting in vibration and accelerated wear above approximately 20 degrees of articulation. A CV (constant velocity) driveline uses a CV joint at the tractor end that delivers smooth, constant-speed output up to 80 degrees of articulation. For applications involving tight turning circles, front-mounted implements, or offset implements, a CV driveline eliminates the vibration and wear caused by steep operating angles.

What is the maximum operating angle for a Bareco CV driveline?

80 degrees at the CV joint end. Exceeding this angle causes CV joint failure and is not covered under warranty. A turning limiter on the implement drawbar is recommended for applications that may approach this limit during headland turns.

Do I need wide-angle at both ends?

Most applications only need a CV joint at the tractor end — this handles the angle during turning while the implement end remains roughly in line with the driveline. Wide-angle-both-ends (WWB series) is required when the implement input is also significantly offset during normal operation, such as some side-discharge mowers. If in doubt, a standard single-CV shaft covers the majority of applications.

What spline does my tractor PTO use?

Most tractors up to approximately 100HP use a 1-3/8" diameter PTO output with 6 splines (the standard on most Australian tractors). Larger tractors from around 100HP and above often use 1-3/4" outputs with 6 or 20 splines. Check your tractor operator manual under PTO specifications to confirm.