> Date:    Sun, 12 Apr 2009 13:50:36 -0700
> From:    neil N <musomuso@GMAIL.COM>
> Subject: Re: Trying To Understand Tie rod Adjustments
>
> The original goal; align things by my "shade tree" hand so I could drive it=
> .
>
> Current goal: see if changing castor on passenger side help RH drift.
> Mostly for learning.
>

Well, it's "caster" to be correct,  "castor" is a bean :-)

IME, caster rarely causes a consistent pulling to one side or the
other.  That's typically camber and/or toe in.
> I will take it to a shop. If my adjustment corrects drift, I'll be
> curious to see how close i got toe and castor. (I'm not dicking with
> the camber)
>
Well, yes you are actually.  If you adjust the caster, you'll be
adjusting the camber as well.  To understand why, just think of a
transverse line running through the two front wheel hubs.  To adjust
caster without affecting the camber, the radius arms would have to be
perpendicular to that transverse line so that when you increase caster
by nudging the control arm rearward, the vertical plane running through
the upper and lower ball joints is not changed (i.e. the lower ball
joint would move *straight* back).  Since the radius arms are at an
angle to that transverse line through the wheel hubs, adjusting caster
also moves the lower ball joint either IN or OUT as well forward/backward.

Unless your tires are already beat, take it to a shop.  It's money well
spent.  Once you start getting a scalloped wear pattern from bad toe
adjustment, or inner/outer wear from bad camber, you'll never get them
to wear right again.

Keith Hughes
'86 Westy Tiico (Marvin)