Installing & Servicing MOOG® Universal Joints

How to Replace U-Joints

MOOG® universal joints are designed with many features that enable them to meet tough OE standards and overcome real-world problems. However, proper installation and maintenance procedures are the key to reliable and extended service life. Learn some helpful tips for installing and maintaining universal joints.

Installation Procedure

Before installation, there are three steps to follow to ensure long service life.

Step 1

Mark components so they can be reassembled in the same position relative to each other. This helps keep the rotational forces in the drivetrain balanced. 

Step 2

Thoroughly clean and inspect all mating surfaces of the yoke for any burrs on the inside of the yoke caused by the removal of the old u-joint, especially the snap ring grooves. This will allow the bearing caps and snap rings to be fully seated upon installation on the vehicle. 

Step 3

Remove, lubricate and reinstall the bearing caps of the u-joint (see photos 1 & 2). The recommended grease for u-joints is NLGI #2 GC-LB lithium complex EP grease, preferably a synthetic. If the recommended grease is not available, make sure to use grease that is compatible with lithium grease. Use care not to lose a needle bearing when removing and reinstalling the caps, and make sure that none of the needle bearings are dislodged before or while installing the cap. 

Once the u-joint is installed on the vehicle, if it is greaseable, it must be greased. There is only enough grease in a new MOOG universal joint to keep the needles in place during assembly; this is not sufficient for keeping everything lubricated for operation. Apply grease until clean, fresh grease extrudes from all four cup seals. 

MOOG u-joints are available with grease fittings in the body or in the cap(s). Look for standard grease fittings (photo 3) or flush-type fittings (photo 4) on the body or caps of the u-joint. If flush-type fittings are used, a needle nozzle should be used.

Maintenance tips

Proper maintenance can extend the life of u-joints. Follow these helpful tips:

• Grease universal joints at every oil change. Wipe the grease gun coupler and grease fitting before connecting them so the bearings aren’t contaminated by the dirt being pushed into them. Slowly add grease until clean; fresh grease extrudes from all four cup seals. This ensures the flow of fresh grease is directed evenly across the bearing surfaces displacing any accumulated debris and allowing fresh lubricant to reach all critical areas

• Inspect the seals for damage. After greasing each u-joint, be sure to clean excess grease away from the seals and grease fitting.

• If the vehicle is used in demanding conditions, more frequent service is required. Any universal joints that have been submerged in water need to be relubricated to prevent rust and corrosion from forming.

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The content in this article is for informational purposes only. You should consult with a certified technician or mechanic if you have questions relating to any of the topics covered herein. Tenneco will not be liable for any loss or damage caused by your reliance on any content.