first ..here is how to adjust the tension with perfect control.
Don't use a lever or bar to pry against the alternator ....that's hokey.
instead..
with some drag on the tension bolt..
use a channel lock pliers to draw the tension bolt toward the end of the
tension bracket.
it should be about an inch  or a bit more of distance.
gives very nice control of setting belt tension,
your not prying on anything etc.

I twang 'em like a guitar string.
'some tension' ...not bow string tight ..
just some twangey tension.
if it slips and squeals cold. ...all else being normal, it's not tight
enough.

if it's really major tight ..yes ....you don't want that.
Always check it again a day or two later ..
there is some 'settling factor'...particularily with a new belt.

scott
www.turbovans.com
----- Original Message -----
From: "Rocket J Squirrel" <camping.elliott@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, August 24, 2011 7:13 AM
Subject: V-Belt tightness -- how to determine?

> Something I've never understood about tightening the belt. Instructions
> usually say something like:
>
> "Be careful not to get the belts too tight. You should have
> slight (1/8" - 1/4") deflection in the belts after they are adjusted.
> This of course depends on the length of the belt."
>
> <http://www.vanagonauts.com/printable.phtml?&catid=215>
>
> How much pressure do you put behind your thumb when testing? I can
> deflect the belt anywhere from not much to a lot more by pressing harder!
>
> --
> Jack "Rocket j Squirrel" Elliott
> Bend, Ore.
> 1984 Westfalia. A poor but proud people.
> 1971 "Ladybug"-brand utility trailer ca. 1972 from a defunct company in
> San Clemente, Calif., now repurposed as The Westrailia.
>
> Sent from my kitchen.