Date: Sun, 05 May 1996 09:14:10 -0700
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: jwakefield@4dmg.net (john wakefield)
Subject: Heater Fan PROBLEM
Frank Condelli wrote:
> My '87 Westy's heater fan has also just died "again."
I sense something of a parallel here. I've been told by my friends in
the medical community that if a human male lives long enough, he WILL
have prostrate trouble, the big scary C. Similarly, it seems that if any
Vanagon is "used too much after it's new," that defectively designed
heater fan bearing WILL seize.
So I figure it's just a matter of time before I too have this poorly
designed assembly apart and ready for my attention.
Now for a moment, and with your gracious permission, I'd like to
address my views of rational RR (replace/rebuild) proceedures in these
kinds of circumstanses. If and only if I were involved in a show
restoration project, would I "turn a blind eye" toward the apparent cause
of the failure being addressed and simply restore what ever the OEM
(original equipment manufacturer) had delivered. Aside from that rare
exception from the norm, I mentally interview and have a dialog with
what I imagine to be likely participants of the original design team.
They typically know a lot that I don't. BUT they are constrained in ways
I'm not (a $3.50 sealed bearing vs. a $.35 open design) and I have
available long-term, real-world performance history information that they
could only try to emulate. Not only that, but I have the right of final
decision.
Now I'd say that in over 99% of these wonderfully instructive reviews,
I go along with the original design team. But, just as I've vocally
advocated completely reevaluating the water cooled (diesel and gas) VW
bus heat rejection systems because I feel they are either inadequate or
marginal at the two extreems of perfectly normal expected bus speeds
(idling and Interstate traffic flow), so too do I feel another bout of
redesign fever welling up within me with respect to these heater fans.
I feel it's natural to solicit collaboration on these issues and we
have a capable collection of talent to bear on these problems.
(I never use the word PROBLEM lightly. My operant definition of the
word problem is A VIOLATION OF EXPECTATIONS. That's very different from
a mere difficulty, which is expected to be difficult. Unlike
difficulties, PROBLEMS demand resolution. Either the relationship needs
to be changed or my expectations need to be changed. Then there is no
problem, though it may become a difficulty. Like raising a 14 year old.)
In the case of these blower fans, I'm not ready to give up my
expectations that a typical well designed blower fan should have a low
failure rate during the design live of any vehicle. I'm also hoping some
of you aren't willing to knuckel under into accepting this glaring
problem. (Notice the intentionally manipulative ego-challenging language
designed to bring some of our heavy hitters "off the bench" and thereby
gain their support? Sorry, couldn't resist:)
Ok, so before I pull my dash apart to look at this blower on my '83
Westie, could someone who's in there with a set of calipers post to this
list the shaft OD, support length, and the surrounding case's potential
bearing support space and opportunities?
I think it would be a very nice addition to this site's FAQ to have a
clear explanation of how to buy manufacturer XYZ's sealed bearing stock
number xxxxxxxx.123 and to make the substituion for the original by
following these steps:
Instead of just "renewing" the original bad design, KNOWN TO FAIL, is
this not the rational approach?
Respectfuly submitted,
John Wakefield
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