Date: Mon, 5 Mar 2001 10:08:00 -0800
Reply-To: Tom Young <tomyoung1@HOME.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Tom Young <tomyoung1@HOME.COM>
Subject: Re: Crankshaft Endplay Defies Me--Please Help
Content-Type: text/plain; charset="iso-8859-1"
I've rebuilt a couple of air-cooled Vanagon engines, which means I'm
an expert by no means, but since when did that stop someone from
offering their opinion? :-)
First, I've always heard and understood that it's best to have 3 shims
in there. It contributes to the "slipperiness" of the set-up and
longer life. (One "outside" shim wants to go one way, the other wants
to go the other (relative to the 1st) and the middle shim provides the
bearing surface.)
Second, I would think that an engine with 80k on it, if it's been well
maintained, probably *doesn't* have and end-play problem, and you may
be obsessing over nothing.
Third, (I'm on shaky ground here, having not rebuilt hundreds of
engines) I'm not surprised that when you release the flywheel it
returns to "0" endplay. Even on a brand-new engine not *every*
surface is perfectly "square" and perfectly "flat" and there's
probably a position that the crank/flywheel assembly "wants" to
return to. (It's been a couple of years since I did my rebuilds, but
I *think* the flywheels in my 2 engines behaved the same way.)
So, I'd say:
1) Assemble your engine without grease, oil or seals.
2) Position your dial gauge toward the center of the flywheel.
3) Shove the flywheel toward the rear of the engine and call this
"0".
4) Pull the flywheel back toward you - some gentle prying with 2
screwdrivers is OK - and take your reading. That's your
endplay.
5) Report back.
----------------------------------------------------------------------
-----
Tom Young tomyoung1@home.com
Lafayette, CA 94549 '81 Vanagon
----------------------------------------------------------------------
-----
----- Original Message -----
From: "Derek Drew" <derekdrew@RCN.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, March 05, 2001 9:07 AM
Subject: Crankshaft Endplay Defies Me--Please Help
> The email below asks whether it is better to violate Bentley by
>
> a) having only one C shim controlling crankshaft endplay even
through
> Bentley says it is important to have two C shims, or
>
> b) whether it is better to drive around with a crankshaft endplay
reading
> of zero (which it would appear my van has had since I bought it new
in
> 1990) despite the spec in the manual that says crankshaft endplay
should be
> 0.004"
>
> I cannot, apparently, have both at once, so I have to choose between
the
> lesser of two evils. Alternatively, I could try to sand down the
edge of
> the flywheel that sits against the motor to provide the desired
endplay.
>
> Please help with comments--more detail below.
>
> ====================
>
> About a month ago I referred to a case where I could not get a
reading for
> crankshaft endplay which I was checking while I was doing my clutch.
>
> The list helped with several comments, principal among them were the
> recommendations that:
>
> 1. No oil or grease should be installed on the shims at all or it
can throw
> the reading off
>
> 2. The crankshaft endplay measurement should be taken at the center
of the
> flywheel, not the edge of it
>
> Boston Bob was particularly helpful with comments, which he
delivered to me
> over the phone. Dennis Haynes, who I consider a real pro, told me
basically
> to stop messing with it and leave it the way it was.
>
> Seeking to resolve this matter, I went back in there this weekend
and
> reinstalled everything with no oil or grease on the shims and took
another
> measurement. The result was that I was still effectively getting 0
(as in
> ZERO) crankshaft end play. I could get a crankshaft endplay only by
flexing
> the flywheel, but after letting go of the flywheel the flywheel
would go
> back to where it had been.
>
> In order to see if I could find out more, I decided to remove the
two shims
> identified in the manual as the C shims (these are the ones that
come in
> various thicknesses) and then remeasure to see if I could get an
endplay
> reading. This worked, and for the first time ever I was actually
able to
> measure an endplay, which was 0.00875". I then installed my other
spare
> flywheel and got a reading of 0.012".
>
> The problem is that both 0.00875" or 0.012" leave such a small space
in
> there that installing the two C shims the way you are supposed to
leaves
> Zero crankshaft endplay.
>
> Either the two C shims that the factory had installed were too large
(thus
> violating their own spec) or I have been losing crankshaft endplay
during
> the engine's first 80,000 miles of life. This later event does not
usually
> happen, however, since the endplay usually increases instead of
decreases,
> according to Dennis and other reports. This is the same engine that
came
> new with the vehicle in 1990. I was composing an email in my head to
send
> to Germany along the lines of, "Yo dudes. You boobed the endplay on
my
> engine!" Sending such an email is not likely to result in a great
benefit,
> so now I have to decide what to do.
>
> Under one strategy I should put those two factory shims back in
there,
> which I determined to be 0.012" thick, and drive around with Zero
endplay
> notwithstanding that the manual says to have at least 0.003" of
endplay.
>
> Or I can decide that the factory goofed and try to put in C shims
that
> provide the correct endplay of 0.004, plus or minus 0.001".
Unfortunately,
> the smallest available C shims are 0.0096" and if I put just one of
these
> in the vehicle, it will bring my endplay down to zero again with the
> resurfaced flywheel I have, and closer to being correct with the
other
> flywheel I have. But the manual is somewhat strident in saying that
you
> must use *two* C shims, not just one. Says the electronic Bentley,
> "CAUTION! Always install three shims to obtain correct crankshaft
endplay."
> (They say three, because they mean to include a third shim that is
there.)
>
> So I have to violate one rule or the other: I either have to install
the
> two thinnest C shims, which are 0.0096" thick each and have zero
endplay,
> or install just one shim and have the correct endplay but be in
violation
> of Beneley's spec that says to use two C shims.
>
> Note for reference that I did these measurements with the seals out
and not
> in the way.
>
> THERE IS ONE OTHER ALTERNATIVE:
>
> I guess I could take the flywheel over to a resurfacer and ask that
they
> remove a layer of the metal that rests up against the shims. This
way, by
> making the mating surface of the flywheel less, I can use two C
shims and
> also meet the manual's spec. Alternatively, I could rest the
flywheel on a
> piece of sandpaper I have here, and spin it around for awhile to see
if
> this technique would cause the desired reduction in thickness of the
> flywheel by, essentially, sanding it away. Not sure if this is
something I
> can do in my garage or whether it requires a special machine to make
it
> super flat. Possibly I could do it with a file.
>
> Any and all expert or inexpert comments solicited.
> _______________________________________________
> Derek Drew New York, NY
> CEO & Co-Founder
> http://www.ConsumerSearch.com/
> ===========================
> "Best Expert Review Site"
> for product reviews on the Internet
> Jan. 2001, PC World Magazine
> ==========================
> 80 South Street, 2nd Floor
> New York, NY 10038
> derekdrew@rcn.com
> 212-580-6486
>
> Alternate numbers for the industrious phone caller that wants to try
every
> avenue: 917-848-6425 (cell); 202-966-7907 (Work), 212-580-4459
(Home),
> 202-966-0938 (Home), 978-359-8533 (fax [efax]), 212-269-3188
(Seaport office).
>
|