Replacing a U Joint

Replacing a U joint (short for universal joint) is a pretty easy DIY job if you’ve got the right tools and things aren’t too stuck together.  If you’ve got a rusty chassis on your car, you might consider hitting things with some penetrating oil a day or 2 before you get started on this job.

Before we get into replacing u joints, let’s talk about how you know if they’re bad!

How to tell if your U joint is bad:

• Put your car in park with e-brake on and grab a hold of your driveshaft.  If you can twist the driveshaft without the yoke on the differential moving then you’ve got a bad u joint there.  Similarly, if there is play up by the transmission that U joint probably needs to be replaced as well.
• You can also hold your foot tight on the brake and shift from drive to reverse and back again.  If you hear a cluck under your vehicle when you do this, it could be coming from play in your U joint.

Now that you’re sure you’ve got a bad U joint, what the video above so you know how to get the job done!

Helpful Hints:

1.  Buy or rent a ball joint press.  You can do the job without one but it can really be a pain.  A ball joint press can easily press the old bearing caps out of the ears of the driveshaft or slip yoke especially if you’ve got an impact wrench to help you along.  If you can’t get your hands on a ball joint press you can substitute a large C-clamp and the right size socket or a bench vise to get the job done.
2. Don’t be afraid to cut the old u joint out.  Since the U joints on your car live out in the open where moisture, grit, and salt can get to them they are often really stuck.  If you have a grinder you can often cut the center of the U joint out making it much easier to get the bearing caps out of the ears of the driveshaft.  Make sure you take the necessary safety precautions and don’t damage your driveshaft!
3. Apply a little grease to the outside of the bearing caps before pressing the new U joint in.  This little bit of grease will go a long way!
4. Make sure the needle bearings stay seated in the new bearing caps.  There is grease on them that helps hold them in place, but if you drop one or get things misaligned the needles can move.  If the needles aren’t all present and aligned after installation your new U joint will fail quickly.
5. If your new U joint has a grease fitting, don’t forget to grease it!  If you don’t grease your new U joint it will also fail quickly.

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pictures provide by:

u_joint.jpg – By Waldemarus – Licensed by Getty Images – Original Link