Part No. 70-3-21X Slip Yoke SPL70 - 1550 SERIES Splines Count 26/27, Splines Diameter: 1.776, Centerline To End: 8.480

Spline geometry is the defining characteristic of a slip yoke, and the 70-3-21X is precisely machined to 26/27-spline, 1.767" specifications for the SPL70 series driveshaft. Correct spline engagement ensures full torque transfer with minimal backlash throughout the operating range.

Spline Engineering

Involute spline profiles, standard in automotive drivelines, distribute torque across all spline teeth simultaneously. The 26/27 teeth of the 70-3-21X provide adequate torque capacity for SPL70 series loads while maintaining sufficient tooth thickness for long service life. Spline diameter of 1.767" is the pitch diameter reference -- verify this matches your transmission shaft specification before ordering.

Dimensional Data

Sliding Surface and Seal Considerations

The portion of the 70-3-21X that slides through the transmission extension housing seal must be ground to a smooth, consistent finish. Surface roughness above Ra 32 will cut through the seal lip prematurely, resulting in fluid loss. Universal Driveshafts sources slip yokes with controlled surface finish on the seal contact area to prevent this failure mode.

Maintenance and Inspection

• Inspect the yoke sliding surface for grooves, pitting, or corrosion at each driveshaft service
• Light surface rust can be polished away; deep scoring requires replacement
• Check spline condition: tooth flanks should show even contact, no brinneling
• Verify the companion U-joint cross and snap rings are also in serviceable condition
• Apply a thin coat of lithium grease to splines before reassembly

Ordering

The 70-3-21X is a stocking item at Universal Driveshafts. We carry the full SPL70 series lineup -- matching crosses, yokes, and flanges. Call or email our driveline team with your vehicle details for confirmation before ordering.

Not sure which slip yoke you need? Our transmission slip yoke guide covers spline counts, styles, and how to measure.