U-Joint Facts

Are All U-Joints The Same?

There are so many different U-Joints, it would take a lifetime of research to put them into one book.


We will try to keep it simple and leave the research to the egg heads.

What difference does a joint make?

Not all joints are constructed the same. Several choices are avaiable.

Greasable Joints and Non-Greasable Joints.



Greasable U-Joints are popular with the budget minded and those who have a strong desire to put a grease gun on everything. The circle track guys prefer the greasable joints. As old grease is pushed past the seals, the racers look for metal as a sign of wear.

Non-Greasable U-Joints are used in applications that require strength and no maintenance. The solid body Spicer joints are found in many OEM applications and it is common to find driveshafts with hundreds of thousands of miles on original joints from the harshest environments (Northern Rust Belt).

What is a U-Joint Series?

There are countless variations of U-Joints that accomodate the different applications and manufacturer design styles. The U-Joint Series is specific to a manufacturer's proprietary design. The most common series will be either inside or outside lock-up, referring to the meathod for retaining the U-Joint cap.

Common Outside Snap Ring U-Joints

Common Inside Snap Ring style U-Joints

Another Category is the Conversion Joint. Conversion Joints cross one series with another.

Examples of some 1310 Series Conversion Joints

Conversion Joints are useful for adapting one series to another. An example is adapting a Spicer 1330 driveshaft to a GM Saginaw style pinion yoke.

U-Joint Manufacturers

There are many different U-Joint manufacturers. As a general rule, we avoid import stuff whenever we can. Sometimes it is unavoidable, and we are constantly checking quality of incoming stock.

The old saying, "You get what you pay for" is still true. Some U.S. manufacturers have lowered their quality to meet the cost of foreign imports. The results are poor fit and performance.

Poor fitting U-Joints affect the center of mass of the driveshaft and prevents the ability to hold a balance.