Date: Fri, 26 Nov 1999 13:09:57 -0800
Reply-To: Coby Smolens <cobys@WELL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Coby Smolens <cobys@WELL.COM>
Subject: Re: dont try this at home
In-Reply-To: <Pine.SUN.3.91.991126071325.16297C-100000@netcom14.netcom.com>
Content-Type: text/plain; charset="iso-8859-1"
Hi, Tom -
I don't think the distributor fits tight enough in its bore for there to be
a clearance problem when it's heated to this degree. After all, an aircooled
engine can easily reach 220 + degrees in normal running, and you can still
adjust the timing when it's hot... Softening the o-ring was the idea.
As for your tractor: Pulling a tight part OFF another is a problem of a
different stripe altogether. Unless you can limit the conduction of heat
from the pulley (for example) to the shaft, which is practically impossible,
you are going to be heating both parts simultaneously - thereby causing BOTH
parts to expand. The physics of heated-pulley removal rely on molecular
excitation to break bonds of corrosion and to create a degree of liquidity
between the separate parts, rather than on increasing clearance between the
parts. If you have a good puller set up and heat the thing enough you'll
definitely get it to come off - the problem may be that sufficient heat to
remove the pulley may damage some other component. Usually, when it comes
the pulley-shaft dance, the thing that works will turn out to be the correct
puller. Or butchery.
On the other hand it is common practice to heat a gear (the camshaft drive
gear for the crank shaft, for instance, or a starter ring gear on a
flywheel) PRIOR to slipping it onto a shaft. In this case it is only the
gear which increases in size, hence also in inside diameter. At first this
may sound counter-intuitive - seems like the thing should swell up and
SHRINK the ID, but I assure you this is not how it works. The entire ring
expands and the ID increases. This is very easy to duplicate for yourself on
the bench, once you get the pesky pulley off you tractor, try heating it
before you put it back on the shaft...
Coby
Valley Wagonworks
"Intimately acquainted with VW Vans since 1959"
Volkswagen Bus, Vanagon, Westfalia and Eurovan
Repair and Service Specialists
1535 Sir Francis Drake Blvd., San Anselmo, CA 94933
Voice:(415) 457-5628
Fax: (415) 457-0967
http://wagonworks.com
mailto:contact@wagonworks.com
> -----Original Message-----
> From: Tom L. Neal [mailto:jneal@netcom.com]
> Sent: Friday, November 26, 1999 7:17 AM
> To: Coby Smolens
> Subject: Re: dont try this at home
>
>
> Hi, Coby.
>
> Warming the dizzy (I didn't know what he was talking about
> until your note) would expand it which would make the problem worse?
> OTOH, maybe the heat would soften the O ring? Interesting technique.
> Heat can do marvelous things. But it can't seem to get a spline
> fit pulley
> off my lawn tractor bearing assembly. I used a torch, but maybe I'll
> put it in some oven and see what happens. Major rust on there.
> Cheers, Tom Neal
>
> On Wed, 24 Nov 1999, Coby Smolens wrote:
>
> > Have you tried warming the thing? You could stick the whole
> distributor in
> > the oven at 250 or so - NOT the microwave, right? - with the o-ring
> > installed on it. Between that and some oil you should be alright...
> >
> > Coby
> >
> > > -----Original Message-----
> > > From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM]On Behalf
> > > Of Jay & Kim Schmidt
> > > Sent: Wednesday, November 24, 1999 12:30 AM
> > > To: vanagon@GERRY.VANAGON.COM
> > > Subject: dont try this at home
> > >
> > >
> > > I replaced my dizzy o-ring tonight and cannot get the dizzy
> reinstalled. I
> > > have my motor on the bench and no amount of pushing, tapping, oiling,
> > > begging, sitting on, etc is making the thing go in. I have to
> warn against
> > > EVER trying this with the motor in the van. I have an
> advantage with it on
> > > the bench, but can't get it to go-it's just tighter than a
> nun's...well,
> > > it's tight!
> > > I hope your results vary.
> > > Jay
> > >
> >
>
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