3102-40 – Flange Yokes – 1310 Series – Bolt Circle Dia 3.250″ – Bolt Hole Dia 0.385

3102-40 Flange Yoke -- 1310 Series Torque Interface Component

At the interface between the driveshaft and the axle flange, dimensional accuracy defines whether the shaft runs straight or vibrates its way to an early failure. The 3102-40 is a 1310 series flange yoke ground to a 4.000" pilot that matches a 3.250" bolt circle companion flange. This combination delivers true, vibration-free rotation from the first mile, not just after break-in. Forged steel construction ensures the part endures the torsional shock loads that shock-absorber-equipped trucks and off-road builds generate during hard acceleration or abrupt stops.

Complete Specification Data

Series Selection and Drivetrain Integrity

Running mixed series components -- a 1310 series flange yoke with a smaller or larger series u-joint -- is a common source of unexplained vibration and premature joint failure. The 3102-40 is engineered to be the termination point for a 1310 series shaft. The ear bores, the ear width, and the material grade all correspond to 1310 series loads. Install it with a 1310 series cross kit and proper grease packing for a drivetrain that performs at rated capacity.

Before You Install

• Degrease the pilot bore of the companion flange before seating the 4.000" pilot
• Inspect all 4 holes for thread condition -- chased threads hold torque better than corroded ones
• Use a flat-blade screwdriver to check companion flange face for warping -- a warped face will transfer vibration through even a perfect yoke
• Set CJ-to-flat at 2.750" -- the cross must not bottom out in the flange recess
• After installation, verify by rotating 360 degrees by hand before lowering off stands

Universal Driveshafts Quality Commitment

The 3102-40 is a stocked item at Universal Driveshafts, not a drop-shipped commodity. Quality is checked before it ships. If you identify a dimensional concern after receipt and before installation, our team responds promptly to resolve it.