Tires: E-350 steering vibration

Question
QUESTION: I have a 2009 E-350 passenger van with a vibration/shake in the front end. I replaced the tires about a year and a half ago by a tire dealer and shortly after that the vibration started. At first it felt like the problem may be shocks, so I replace them. After that, I took the van to my mechanic, the dealership, and back to the original tire dealer to inspect the front end and tires. ALL said the tires were out of balance and re-balanced the tires each time. I also had the front tires replaced a couple months ago by the tire dealer and still have the problem. What should I look at now?

ANSWER: Brian,

First, is the vibration coming through the steering wheel (front tires) or though the seat (rear tires).  I'm guessing front based on your first sentence.

If so, then rotate the tires.  That should change where you feel the vibration.  If it doesn't change, then the problem isn't likely tires and wheels.

But some more diagnostics.  If the problem was the tires, the problem would have started IMMEDIATELY after changing tires, not sometime later.  So I'm guessing the problem is somewhere else.

Also, wheel end related vibrations (tires, wheels, and other rotating parts) tend to occur between 50 and 70 mph and not at other speeds.  So if your vibration isn't confined that speed range, it is also not likely tires or wheels.

So if it isn't tires, what is it.  For the answer to that question, we need more information.  Is the vibration speed related?  Does the vibration occur when the engine is rev'd in neutral?  Does the vibration occur at different speeds depending on what gear your transmission is in?

Answer to those questions will help narrow it down.



---------- FOLLOW-UP ----------

QUESTION: First, yes I can feel the vibration in the steering and also in the front floor board. The vibration seems to start 40-50 mph and worsens as the speed goes up.

Second, the thing that I found strange was that I had the tires checked and balanced 3 times within about 2 weeks at 3 different places, and each time they were way out of balance.

I will rotate the tires and check the other things you mentioned and follow up. Thanks.

Answer
Brian,

40 mph is a bit low for a wheel end vibration.  The fact that you can feel the vobration in both places, kind of says it is something else.

Also, tires tend to stay balanced.  So if they were out of balance more than once, this may be part of the problem.  So I wonder what is going on with the shop's balance machine (or procedure.)