[Richard]

And from someone who has had his hands on it. Don't believe anyone who tells you they can check them in place. When I had u joint issues, I tried to detect play using a 36" pry bar. Nothing. However, when I disconnected the driveshaft, I could clearly feel the notch in the bearings when I moved the joint.

And so, before a wave of u joint paranoia hits, here is how early u joint problems will manifest. On a perfectly smooth highway, you can feel a subtle vibration in the floor or seats. It will vary with highway speed, and mine would only vibrate at 67 to 70 mph. Slower, no vibration, and faster no vibration. It will be more pronounced going up a slight grade. You can feel it more in the floor over the drive tires also. On our coaches the u joints are a highly stressed component, perhaps the most stressed part on the whole coach, except maybe the copilot.