The Universal Joint and the Driveshaft
The universal joint or U-joint is one of the lesser known components on the car. It shares similarities with the CV joint but it is still very different. It works as a flexible coupling for both ends of the driveshaft. A U-joint has a four-legged center cross with needle bearing cups on each end. One pair of bearing cups is connected to the driveshaft and the other pair is held in place by being connected to the transmission or differential (depending on if your vehicle is rear-wheel drive or four-wheel drive.)
The bearing cups enable the U-joint to have a range of motion to bend and swivel as the driveshaft follows the differential as the suspension bounces up and down.
Sometimes it can be hard to identify the source of a problem with your car. A vibration, strange sound, or leak each has a number of different components that could be the cause of the problem. Even then you could experience all three at the hands of a U-joint failure.
Vibration usually occurs around 25-35 mph and when braking at low speeds. You may sometimes hear a “clunking” noise when shifting into gear and it could be caused by a bad U-joint or by a differential problem.
The main culprit is usually a loss of lubrication in the U-joint. It may have gotten loose or damaged but either way it is losing grease which in turn is increasing the friction which will wear it down over time.
Thankfully U-joint replacement is relatively easy if you’re an amateur mechanic. However you first need to get to the U-joint in order to remove it. In order to do this you’ll need to remove the driveshaft. Driveshafts can differ but more than likely you’ll need to remove the holding bolts to get the driveshaft off.
The next step is to remove the C-clips so you can press the bearing and joint out. Now you should be able to remove the bearing cup from the U-joint and replace the old one with the new one. Once it’s been replaced it can then be reassembled.
Some of these steps may require more detail depending on how old your vehicle is and the make and model. Before you start pulling things out from under the hood it would be wise to bring your car to 2J’s Automotive and let our certified mechanics take a look at it for you.
We will give you a FREE diagnostic test ($80 value) that most other shops will charge you for and we will find out what exactly is giving you problems on the road. Once the problem has been identified we will inform you of your options and offer recommendations so you can drive safe and have peace of mind.
Give us a call at 817-232-9866 if you have any questions or would like to set up a time to come in.