Date: Tue, 26 Jan 2010 00:04:29 -0500
Reply-To: David Beierl <dbeierl@ATTGLOBAL.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Beierl <dbeierl@ATTGLOBAL.NET>
Subject: Re: heater fan whine
In-Reply-To: <514530.43602.qm@web33505.mail.mud.yahoo.com>
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At 11:32 PM 1/25/2010, Robert Keezer wrote:
>C'mon guys, this is classic thread hijacking. The OP asked how to
>fix the whine in the motor, not load reduction. I want to know the
>answer also.
Robert, I'm accustomed to hearing a low whine from the front blower
(on several different installations) as a normal thing at speed 1;
disappears at speed 2 or 3. Otherwise I've no experience with
whining noises from the blowers -- just ticking or squeaking or
squealing or chattering or trouble coming up to speed or complete
seizure -- all dry-bearing symptoms. All of those things are cured
by lubricating or replacing the motor. (In a different vehicle I've
seen the most awful ruckus when a huge mouse nest fell into the
upturned blower wheel.)
The cure for a dry bearing is oil and there have been about a
gazillion threads on how to oil or replace the motor, or make it
possible to oil it without taking the heater box apart. Some people
have recommended simply replacing the motor; but my experience with
four or five motors is that aside from the dry bearings they're in
great shape -- commutators look good and the brushes are hardly
worn. Someone mechanically inclined can separate the blower shell,
drive or press the blower wheel off the motor shaft and have good
access to the bearings to clean them up and refill the felt pads with
oil. When pressing the shaft out you must support the blower wheel
and not the motor; and when replacing it you must support the
opposite end of the shaft. Otherwise you can drive the armature and
commutator off the shaft.
If the problem hasn't progressed too far, Karl Mullendore figured out
a nifty way to get access to the after bearing, which is the one that
takes the most beating. It's a stopgap, but a good one -- if you
catch it while the motor is making noises but still running up to
speed. There's a link to it a few messages back. You can't get to
the felt, but something like Tri-Flow will wick into the bearing
itself so it runs smooth.
If the motor has actually seized it will have to come out and get the
guck cleaned out of the bearings; and if it's chattering it will need
new bearings, which in practice probably means replacing it.
But for whining I really don't have a clue.
Yours,
David
