nelsoninmaryland@aol.com wrote in article
<1131453209.536884.120640@o13g2000cwo.googlegroups.com>...

I think the answer lies in your question....It's the "XLT trim" that has
gone out of aero-dynamic balance.

It has been known for years that the harmonics of the XLT trim create
oscillations between 63 and 75 m.p.h., yet Ford continues to look the other
way.

Look for a product claiming, "....never wax your car again!" The secret,
non-waxing polymers in these "never wax" products tend to control the
chaotic oscillations of the XLT trim by allowing air to pass over without
creating any aero-dynamic lift.

Sorry!

Since the term "XLT trim" was included - as if it might contribute to the
problem - the temptation was too great.......

Tires and wheels don't have to be round to be balanced, but being
out-of-round will cause vibrations. Since the tires are new, (and
presuming that the problem wasn't there before), tires would be
the first suspect. There may be a manufacturing defect.

Another possibility is that the wheel and tire high spots are
aligned, again creating an out-of-round situation. This can usually
be solved by re-mounting the tire at roughly 180 degrees from where
it was mounted. The assembly must be re-balanced of course.

The wheel may also have a small flat spot that didn't cause problems
before, but is now. If it is a steel wheel, the tire shop might try
to hammer it out, but replacement is probably a better idea. If it
is an aluminum wheel (ah, the XLT trim!), then a wheel repair shop
can probably straighten it.

There are other more obscure possibilities, but these are the most
likely given that you have new tires.

Dan

(This account is not used for email.)

   Since the steering wheel picks up the vibration, that indicates
one(both) front tire(s) is(are) improper--may just need re-balancing; or, it
may be out of round. Like another poster so aptly put it, even a square tire
can be balanced, although it will not ride smoothly.  If this be the case,
it needs trueing and then re-balancing.  HTH, s

Take it back for a re-balance and ask the tech to look carefully for
any out-of-round or wobble in the tire and for any indication of a bent
rim when on the balancing machine.