1302-37 – Flange Yokes – 1351 Series – Bolt Circle Dia 3.661″ – Pilot Dia 1.811, M

Flange Yoke 1302-37 -- 1351 Series, 3.661" Bolt Circle

Sourced directly from the drivetrain component specialists at Universal Driveshafts, the 1302-37 is a 1351 series flange yoke machined to consistent, measurable tolerances. It is purpose-built for applications where the driveshaft must bolt directly to a companion differential or transfer case flange rather than slip over a spline. The 1.811" male (raised) pilot feature ensures immediate concentricity the moment the yoke is seated.

Technical Data

How the Bolt Circle Drives Compatibility

The 3.661" bolt circle is the defining compatibility dimension -- it must match the companion flange exactly. Attempting to use a yoke with a different bolt circle leads to misaligned holes, requiring elongation that destroys the precision fit. The 1302-37 is stocked specifically for flanges with a 3.661" PCD, so there is no guesswork at the bench. It ships with 4 bolt holes of 0.445" diameter, ready for standard or metric hardware depending on your vehicle platform.

Pre-Installation Checklist

• Measure companion flange bolt circle -- must equal 3.661"
• Confirm pilot diameter of mating flange matches 1.811" male (raised) pilot
• Check that your u-joint series is 1351 -- cap size compatibility is non-negotiable
• Verify CJ-to-flat (1.750") against cap depth in your u-joint to prevent interference
• Clean and de-burr both mating faces before final assembly

Build Quality

Every 1302-37 is forged from carbon steel for grain-flow strength, then machined to finished dimensions. The ear bores are sized for 1351 series cap diameter -- no reaming required. Whether this is a stock replacement or part of a custom high-performance build, the part will handle the torque loads the 1351 series was rated for without deflection or fretting at the bolt faces.