027SG80004 – Cv Double Joints Heads – Bolt Circle Dia 3.386″ – Bolt Hole Dia 330″ – Pilot Dia 3.937

When a driveshaft must operate at angles exceeding 3-5 degrees continuously, a conventional Cardan joint introduces measurable speed variation at twice the shaft rotation frequency. The 027SG80004 solves this with a double-joint constant-velocity head in the CVJ series -- the industry's proven approach to high-angle driveshaft applications in off-road, military, and commercial vehicle platforms.

Dimensional Specifications

How CV Double Joints Eliminate Vibration

A double-Cardan joint achieves constant-velocity motion by arranging two single U-joints in series, phased so that each joint's velocity variation is equal and opposite to the other's. A centering ball-and-socket assembly maintains the midpoint angle precisely at half the total operating angle. The result: velocity error at the first joint is exactly cancelled by the second joint, and the output shaft rotates at a perfectly constant speed regardless of the total operating angle -- up to the joint's rated maximum.

The 027SG80004 is rated for continuous operation at angles typical of lifted trucks and transfer case applications, and is grease-serviceable through standard U-joint Zerk fittings to extend service intervals in demanding environments.

Tube Welding and Assembly Considerations

The butt-weld end of the 027SG80004 is machined for 2.500X0.065 driveshaft tube. Proper weld preparation -- clean, square-cut tube ends, correct gap, and a preheat in cold conditions -- is as important as the joint selection itself. A poorly welded joint head introduces runout that no amount of dynamic balancing can fully correct. After welding, the completed shaft should be balanced to within 0.1 oz-in per foot of shaft length for best NVH results.

• Verify the bolt circle diameter and hole count match the companion flange before final assembly
• Grease the centering socket and both bearing crosses at initial assembly and every 30,000 miles thereafter
• Check for centering socket wear if vibration returns after lubrication -- a worn socket allows the midpoint angle to drift, degrading velocity cancellation
• Maintain proper driveshaft phasing (yoke ears in-phase) when assembling the complete shaft

Order from a Driveline Specialist

Universal Driveshafts stocks the 027SG80004 and the full range of CVJ CV joint components for same-day shipment. Our driveline engineers can assist with angle measurement, tube selection, and complete shaft specifications for custom build projects. Contact us with your vehicle's operating angle and torque requirement for a personalized recommendation.