Proper Lubrication of U-joint: What Does Fresh Grease at Trunnion Seals Indicate?
What does the appearance of fresh grease at all four trunnion seals after lubricating a U-joint indicate?
The appearance of fresh grease at all four trunnion seals after lubricating a U-joint typically signifies which of the following?
a) the U-joint has been properly lubricated
b) the bearings are worn and should be replaced.
c) the seals are worn and should be replaced.
d) the trunnions are worn and the U-joint should be replaced.
When lubricating a U-joint, if fresh grease appears at all four trunnion seals, it indicates that the U-joint has been properly lubricated. This is a positive sign that the lubrication process was successful and the grease has reached all necessary parts of the U-joint.
The presence of fresh grease at the trunnion seals is a good indication that the bearings inside the U-joint have received adequate lubrication. This does not necessarily mean that the bearings, seals, or trunnions are worn out.
Inspecting the U-joint for wear or damage is still necessary even if fresh grease is visible at all four trunnion seals. However, in general, this outcome suggests that the U-joint has been properly lubricated and no immediate action is required unless there are visible signs of wear or damage.