I've gone through the same situation.  Betcha you have a loose wheel
bearing.  Especially if you've had the front bearings repacked.

Karl Wolz

> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
Behalf Of
> Kim Springer
> Sent: Sunday, September 11, 2005 9:33 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: vibration
>
> Hello list,
>
> After looking into tires I decided to buy Mich. LTX MS 195/75-14.
>
> I had them mounted and balanced.  What a quiet tire, feels good on the
road..I'm
> happy.
>
> Only thing, a vibration that I think is tire balance.  So I have the
front end checked.
> Done with crow bars according to the mechanic...it all looks fine they
say.  Not a
> surprise as the Tristar only has 75K miles on it.
>
> So back to the tire shop and they "road force" balance the tires.  One
is a bit out
> (not a great tire but OK, rim is fine), they rebalance them all.  They
put the worst on
> the rear.  The ones on the front are perfect, so they say.  This is a
very reputable
> tire shop.
>
> I still have the following issue: At 75mph I really have a shaking
steering wheel.
> Some of the time at 65mph it's smooth but sometimes get to shaking
again.  If it's
> smooth, and I'm going straight, it seems like it stays smooth.  If I
take a curve (on
> the freeway), then it will start to shake.
>
> My gut feeling is that if the tires/wheels on opposite sides of the
truck are in
> positions that are "happy together", then all is well.  If I take a
curve and the tires
> move to a different position relative to eachother, then things start
to vibrate again.
>
> I can't believe that is the actual issue.  I've never had anything
like this before.
> Anyone out there ever dealt with this?  What's next?
>
> Kim Springer
> '89 Tristar 2WD White.