I have seen this frequently on both Michelin and Yokohama tires on various
vehicles. Seems fairly common on Continentals also.The tire must be taken
out of service ASAP as it fail here. It is a PLY separation caused by the
movement of the steel belts actually cutting the tire.  Better designed
tires will actually use a nylon cap on the sides of the steel belt to
prevent this.

Dennis

----- Original Message -----
From: <RAlanen@AOL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Saturday, December 04, 1999 12:36 PM
Subject: Yokohama tire report

>     Just a little performance report on the Yokohama Y370 LT195/75R14
tires I
> had installed on my '87 Westy.  Installed June 21st, 1997 at 276,200 km
now
> at 234,991 km, (51,209 km) I have just encountered a problem.  Left front
> developed a large bulge on the outside portion on the tread.  About from
the
> middle of the tread and about 8" in length.  Causing pronounced steering
> troubles.  I have now put the two front tires on the rear and all is fine.
I
> am trying to contact Yokohama to see what they have to say about this.
> Meanwhile, have any of you ever experienced anything similar, with your
> Yokohamas on your Vanagons ?  Appears to be a ply separation from what I
can
> see.
> Well, now to see what Yokohama has to say ????  Anyways, these tires are
> about done so one new tire won't do so guess I end up getting four new
> ones........No other problems encountered with these tires.  Handling was
> always excellent until the bulge started making the front end twitch
around
> especially on wet roads and windy conditions......pretty scary !  Traction
in
> wet and snow conditions was otherwise good.  Don't know whether or not to
go
> for another set of Yoko's or a set of Michelin Agilis 61's.
> Checking...........
>
> Cheers
>
> Frank Condelli
> '87 Westy
> Almonte, Ontario
> Visit me on the web........ <A
> HREF="http://members.aol.com/RAlanen/index.html">Frank, Rita & April's
Website
> </A>