6. Alignment: Excess camber can also cause it. You should take your coach to a qualified alignment shop as soon as possible, because something may be coming loose. Interestingly, people often think that their coach is out of alignment because it’s shaking, but that’s usually a tire/wheel problem.

7. A bad U-joint: The U-joints all have to be lined up so they are in phase. Part of the “phasing” procedure includes making sure that the center lines of the transmission and the rear axle drive shaft are parallel. If the axis of the pinion gear is parallel with the ground, then the tail shaft of the transmission must also be parallel to the ground. It can be higher or lower but it MUST be parallel. If the technician knows what he’s doing, he can look and see that the U-joints are properly phased. If they are not properly phased, you will likely experience vibration.

8. A bad CV joint: Basically, a CV joint allows a vehicle to maintain continuous power along turns, without which, front-wheel drive would not work effectively. The symptoms of a defective or worn out CV joint usually occur when driving at highway speeds (55 – 75 mph). This is something you might notice when driving at that speed, if you turn the wheel slightly to one side or the other and the vibration gets worse (or better if it’s an inner CV joint problem). Once you turn the wheel straight again, everything’s fine. That’s a clue that you may be dealing with an inner CV joint problem.

9. Out of line drive shaft: A driveshaft can also be out of round, so you should check it for run-out with a dial indicator and see if that is the problem. If you’ve had your u-joints replaced, that throws the driveshaft out of round, which causes a vibration, so if you need to address both components not just one.

10. Low transmission fluid level: With an automatic transmission, you can start by checking the fluid level and condition. If the fluid is low, top it off and recheck for the vibration. If it’s gone, consider yourself fortunate and try to find where the fluid went.

Like anything else, finding and solving vibration requires a systematic approach. Everything is connected and affects the performance of everything else over time. When checking for vibration, don’t stop checking when you find just one of these issues. You could easily have multiple factors compounding the situation. Treat you coach like the complex system it is and it will serve you well for many years.