Was this cracking of the sidewall or where the tread meets the sidewall? Big difference. Tread separation and the steel belts working out can be a design or manufacturing defect but that usually occurs on both sides unless there is also an alignment or other issues. Same for under inflation. Sidewall checking or cracking on the inside only can be indication of fluid contamination. Brake fluid in particular does a number on tires over time.  

For alignment there are a number of mounts and bushings that go bad that will allow the alignment to change under load. The front radius rod mounts are a biggie. They may almost look good but they get compressed and allow the caster angle to change drastically and this will side load the tires during turns. If you don’t know when they were done last they likely need it. The upper control arm bushings are another sneaky cause of alignment and tire issues. I just had one (new) fail during a trip and completely trashed a pair of Nokian tires in about a 1,000 miles.  That was a very expensive bushing. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Michael Hart
Sent: Thursday, November 20, 2014 8:25 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Please Check your Nokian Tires

If you have Nokian tires, please check them.
My 3 year old Nokian Hakka C 205/70R15 tires had horrible cracks on the inner sidewalls.
Quarter inch wide cracks running most of the way around the circumference of the tire, the tire wires sticking out.
Just 30k miles and absolutely no signs of damage on the outer sidewalls.
All four tires were affected.
They have been replaced by Nokian (pro-rated rate) now, apparently a manufacturing defect.
Very scary to find this after a 70mph freeway trip back from the sierra.
You will only see the damage by looking under your van or removing the wheels (I was changing brake pads when I found this).....
I'd be interested to hear from you (pmail) if you have a similar experience.
I did find other reports on thesamba.

Michael Hart
Palo Alto, CA
'87 2WD Westfalia ('T3WESTY')