Date: Wed, 23 Sep 2009 13:15:02 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Front tire wear
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reply-type=response
re
" Vanagons have > +4° positive caster, meaning the bottom ball joint is
closer to the rear of the van than the top one is. "
I believe it's the other way......
the lower ball joint is further forward than the upper ball joint.
That angle contributes to a self-centering affect easing off the steering
wheel coming out of a corner.
- similar to a bicycle front fork, somewhat.
it's interesting how castor works.
You can easily check if it's the same side to side.
Using a level and short ruler to tell how far from vertical the wheel rims
are .......
look for slight positive camber ( leaning out at the top ) on both front
wheels when they are straight ahead. Like the top of the wheel rim might
be 18th or 1/4 inch further outboard that the bottom is. And it should be
close the same on both sides.
then turn the wheels pretty far right. Then check how vertical the wheel
rims are again.
You should find that turned right, the right front outer wheel leans way out
.........like two inches,
and the left front leans in just a bit, like 1/2 inch about, or maybe a bit
less than one half inch.
turn the wheels the other way ..........measure again.
If it's the same on both sides, and roughly close to what I described, and
straight ahead camber is about right - ( just a little positive ) your
castor is about right.
and no one ever does this that I know of, but seems to me the driver's
weight should really be simulated while measuring things. Check how much
straight ahead camber changes with and without the driver's weight in the
van. Or with two passenger's worth of weight in it, .......but unladen is
what's usually done.
Toe is very easy to check toe too.
Scott
www.turbovans.com
----- Original Message -----
From: "Keith Hughes" <keithahughes@Q.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, September 23, 2009 10:38 AM
Subject: Re: Front tire wear
>> Date: Wed, 23 Sep 2009 09:39:20 -0400
>> From: "Jack R." <jack007@COMCAST.NET>
>> Subject: Re: Front tire wear
>>
>> William,
>>
>> My 84 has the same issue, and when I brought it in for an alignment last
>> year after changing the front PS rack,
>> they indicated that the negative camber was 1.5 degrees out of
>> adjustment,
>> and could not be corrected beyond that without some major front end work.
>>
> Vanagons should not have "negative camber" unless fully loaded, and then
> only 1/2°. So if you're saying you *have* 1.5° negative camber, under
> normal load, then you do have some problems. Unless something is really
> bent, only ball joints, control arm bushings, and camber adjustment
> affect camber (well, or wheel bearings just about to fail). These are
> fairly easy to check. Also, I'd make sure your alignment shop *knows*
> vanagons. When the camber adjustment gets nocked out of whack, it will
> always go negative - thats the normal state if you loosen the locking
> bolts. When you take a vanagon with a loosened camber adjuster into
> 'jiffy alignment', the 18 yo "tech" will almost always look at the
> massive negative camber and say "Whoa! no way to adjust this!". BTDT -
> you have to tell them to go ahead and try anyway, because there is a
> great deal of adjustment range on Vanagons, much more than most vehicles
> I've seen. So if your ball joints and bushings are OK, it should be
> alignable.
>
> As for tire wear on the edges of the tire - greater wear on the inside
> and outside edges is normal, especially if you don't rotate regularly,
> . Vanagons have > +4° positive caster, meaning the bottom ball joint is
> closer to the rear of the van than the top one is. Since the tire
> rotation axis (left/right) is the line drawn between the centers of the
> ball joints, and that line is not vertical, whenever you turn the
> wheels, the camber changes (i.e. the wheel tilts), so some additional
> wear on the inner/outer edges is expected. If the wear is greater on
> one edge than the other, or if there is cupping or feather edging as
> well as wear, or you have really significant wear, then you have
> inflation, or alignment problems.
>
> Keith Hughes
> '86 Westy Tiico (Marvin)
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