Should New U-Joints Be Tight (Or Stiff)?

Before installing a replacement part, you always want to make sure that the part is working right. When you’re dealing with universal joints, you may be concerned with how stiff they feel when moved by hand.

You may be wondering if you bought a defective u-joint. If you’re in this situation, rest assured that it’s normal for new u-joints to feel somewhat stiff.

New U-Joints Should Feel Pretty Stiff When Moved By Hand

U-joints are precision bearings. That means they should move freely in both axis. Yet, it’s normal for a new u-joint to feel pretty firm when you move it by hand, even when it is thoroughly greased. When installing the new u-joint, after you get the first two caps in the yoke, gently tap the joint back from each side. Do this after pushing the caps into place and installing the clips. Tapping the joint back from each side ensures that the caps are tight against the clips. This may loosen up the u-joints a little.

If a new u-joint gets stuck while you move it by hand, that’s bad. Also, any “catching” in the movement is not good. If you notice either problem, pull the joint and check the bearing to make sure none of them have come out of place. As long as your new u-joints create a smooth motion with no sticking, it should be OK to feel some stiffness.

U-Joints Loosen Up As They Wear

You may have noticed that your old u-joints feel a lot looser than the new u-joints. It’s because u-joints loosen up as they wear. As a u-joint wears, the grease in it breaks down. Are you worried about your new u-joints being too stiff, even though they create a smooth motion with no sticking? You can check them again after a couple of weeks of use. They’ll almost certainly feel looser. After that initial break-in period, they should feel the same for a long time.

Be Careful Not To Press The Caps In Too Far

When installing a new u-joint, be careful not to press the caps in too far. When this happens, the end of the cross will ride against the inside end of the cap (until the cap presses out against the c clip). This can cause the u-joint to fail. (Other reasons for failure here.) The caps should be pressed in just far enough to get the retaining clips installed.

It’s important to replace bad u-joints right away. It’s also equally as important to install your u-joints the right way.