Bulletin: Measuring Universal Joints for Driveshafts

Universal joints (U-joints) play a critical role in driveshaft assemblies, facilitating smooth torque transmission between shafts at different angles. Ensuring accurate measurements of U-joints is paramount for optimal performance and compatibility in driveshaft applications. Follow these comprehensive steps to measure universal joints accurately:

Identification Procedure:

Step 1: Find the Style of U-Joint:

• Examine the driveshaft assembly to identify the specific style of U-joint utilized. Common types include:Cross and roller U-joints: Recognizable by their cross-shaped design with roller bearings at each crossing point.
• Inside and outside snap ring U-joints: Feature snap rings on the inside or outside of the bearing caps for retention.
• Staked/Welded U-joints: Caps may be staked or welded to the cross for added security.

Step 2: Measure Bearing Caps:

• Utilize a precision caliper or ruler to measure the diameter of the bearing caps. Take the measurement across the widest point to ensure accuracy.
• Record the measurements of both bearing caps, noting any deviations in size between caps.
• If possible, remove the old universal joint that needs to be replaced so it can be identified by style and measured.

Step 3: Measure U-Joint Assembly:

• Determine the total width of the U-joint assembly by measuring from the outside edge of one bearing cap to the outside edge of the opposite bearing cap.
• Additionally, measure the distance between the centers of the cross and record this measurement.
• Take note of any auxiliary features such as grease fittings, retaining clips, or markings for orientation.

Additional Tools Required:

• Calipers: Essential for precise measurements of bearing caps and other components.
• C-Clamp or Vise: Useful for securely holding the U-joint assembly during measurement and replacement processes.

Many times, universal joint part numbers cannot be easily identified, especially by application. Therefore, mastering the measurement process is crucial for ensuring the correct fitment and performance of your driveshaft.

1. By meticulously following these steps and utilizing the recommended tools, you can ascertain precise measurements of universal joints for driveshafts, guaranteeing proper fitment and reliable operation. Should you require further assistance or detailed specifications, refer to the manufacturer's documentation or consult with a knowledgeable technician specializing in driveshaft components.