Date: Tue, 26 May 1998 23:42:18 -0400
Reply-To: Derek Drew <drew@INTERPORT.NET>
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: Derek Drew <drew@INTERPORT.NET>
Subject: Re: Syncro Alignment Spreadsheet
In-Reply-To: <158F8451EC2@msvu1.msvu.ca>
Content-Type: text/plain; charset="us-ascii"
My page 44.5 says that to set toe for front axel to simply set the toe
according to page 44.3a. But you have typed some specs in there. I am not
sure why or where you got these specs. In researching this question, I find
that your specs come from the early Bentley manual, the 1980-1987 manual.
But the later vanagon manuals 1980-1991 do not quote these figures and
instead gave a revised method of determing this spec, and the result is the
44.3a measurement. So we have the following table:
Empty / Full Load
1987 spec 0 degrees minus 10 mins/0 degrees plus 12 mins
revised 1991 spec 0 degrees minus 2 mins/0 degrees minus 2 mins*
*assuming all North American vans are maxed out on the 44.3a spec, which
they seem to be.
So it would seem that one effect of VW's revised toe specs for syncro is to
prevent us from aligning the vehicle in accordance with any kind of full
load spec which had been allowed previously, to go up to 12 mins. But it
seems silly to limit us to 0 degrees minus 2 mins regardless of load, so
the 44.3a spec needs to be viewed with great suspicion.
Possibly we should ignore the revised spec and assume VW's brain was out to
lunch when they revised the methodology for determining front toe spec. Or,
if we decide we like 44.3a, and that VW had a reason for introducing this
methodology, perhaps we need to ignore this sentence: "If measured distance
a falls outside of the range ion the graph, use use the last toe
specification shown on the appropriate end of the graph." That is, VW seems
to have forgotten about the possibility of having half laden vehicles
measured when they made up 44.3a, and I believe it is possible we should
plot an extension of the 44.3a graph. By doing so, the revised 44.3a spec
will no longer seem that different from the 1987 spec. Possibly you should
consider plotting an extended 44.3a graph for this purpose.
Typical wheelwell 44.3a measurements under a variety of conditions and
typical Westfalia loads (but with the van mostly emptyish) I have obtained
are never within the grid provided on 44.3a. They are always off that
scale. This applies even to non-GL, non-Westfalia syncros. Typical
measurments are 460. I have a rather large database of these measurmeents,
and if you like, I can email you a Word doc with that database.
One would have hoped that the 44.3a measurements would have had a stronger
relation to the 1987 specs. The fact that it doesn't, calls both into
question. I think we need that california fellow that was so happy with is
expensive alignment to supply us with a printout of the specs that he got
from his alignment.
==========================
OK, on to other business. Other errors I see on your rendition of page 44.5
are that in later versions of Bentley they changed the Maximum permissible
difference between sides from -20 mins to simply 20 mins. I assume they did
this for the obvious reason that it is silly to specify negative 20 mins
difference when the mere difference of 20 mins is sufficient. You appear to
have the rest of the page right, although there is no plus or minus sign in
the full load castor box. That spec is simply "+3 degrees 35 minutes".
Well, there are some errors on your rendition of page 44.2, but these
errors are in a way unimportant since, as you pointed out, this page 44.2
is for non-syncro.
Your rendition of page 44.3a is a no brainer and looks fine.
The reason I gave the sequence of adjustment 1) Castor, 2) Camber, 3) Toe
is that this is the sequence Bentley says to do it on on page 44.3. I just
lifted this from Bentley.
I am going to forward this post to the vanagon list because, although it
must be for most the most boring document published yet on earth, if we are
to use the resulting specs seriously it would be well to have documented
our conversations in analyising the issue.
_____________________________________________________
Derek Drew New York, NY & Washington DC
ConsumerSearch
drew@interport.net
212-580-6486 (W)
212-580-4459; 202-966-0938 (H)
