What is lubricating the U-joints all about?
U-joints, or universal joints, are found along the driveshaft or driveshafts of a vehicle, at any point where the driveshaft has to change angle or attach to another component such as a differential. This type of coupling is capable of withstanding large amounts of torque. Proper lubrication ensures that these parts don’t experience any excess friction and won’t wear out prematurely.
Keep in mind:
- If the U-joints show signs of excess friction, they should be thoroughly inspected to make sure they don’t have to be replaced.
- These parts are under very high stress. Any issue with a U-joint should be addressed immediately.
- By the time there are noticeable signs that the joints are bad, parts might already be damaged to the point of needing replacement.
How it’s done:
- The vehicle is raised and supported on jack stands
- The U-joints on all drive shafts and steering shaft are located
- The Zerk grease fittings on the U-joints are located
- New grease is pumped into the grease fittings with a grease gun
- The vehicle is lowered off of the jack stands
Consult the vehicle’s manual for any manufacturer suggestions as to how often the U-joints along the drivetrain need to be inspected. Each time they are inspected, they should be lubricated. While the mechanic is underneath the vehicle, they should also inspect the driveshaft and other parts of the drivetrains to make sure that any symptoms of a U-joint issue weren’t actually caused by something else. For example, vibrations could be caused by an unbalanced wheel or damaged tire.
What are the common symptoms indicating you need to lubricate the U-joints?
- Clicking noise coming from under the vehicle when in gear
- Vibrations in the vehicle
How important is this service?
This service is extremely important if the vehicle is showing any signs that the driveshaft or U-joint is not functioning properly. These parts are under a massive amount of torque and the failure of a spinning shaft is very unpredictable.