U-Joint Size Identification

U-Joint Identification Guide – Measure & Match with Confidence

Whether you're repairing, replacing, or upgrading your driveline, identifying the correct universal joint (U-joint) is critical for proper fitment and long-term reliability. At Tom Wood's, we've made the process easier with our new U-Joint Size Measure & Match App.

Use the Tool: Measure & Match Your U-Joint

Our interactive tool walks you through identifying your U-joint based on:

• Cap diameter
• U-joint width
• Clip type (inside or outside)
• Common part numbers and vehicle applications

Why U-Joint Sizing Matters

U-joints come in dozens of sizes and styles, from Spicer 1310 and 1350 series to metric joints used in many import vehicles. Even a few thousandths of an inch in cap diameter can make the difference between a secure fit and premature failure.

How to Manually Measure Your U-Joint

For best results, use calipers. A measuring tape can work, but you'll need to convert fractions to decimals (e.g., 3 5/8" becomes 3.625").

Determine the clip type:

• Inside clips (snap rings) sit inside the yoke ears.
• Outside clips rest on the outside of the bearing caps.

Take two key measurements:

• Cap Diameter – Measure the outside diameter of one bearing cap.
• U-Joint Width – Measure from the outside of one cap to the outside of the opposite cap, across the joint. Or for joints with inside type snap rings measure from snap ring to snap ring. 

Common U-Joint Size Chart with Series and Applications