Date:         Mon, 22 Apr 1996 10:26:00 -0700 (PDT)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "Maher, Steve (SD-MS)" <SMAHER@gi.com>
Subject:      V6anagon re-V6'ed, finally, mostly


Did the deed(s) on the V6anagon over the weekend, while not at T-ball
games or riding bikes around various lakes and feeding ducks with son.

Measured the distance of the ridge machined in the engine adapter, from
the surface of the crankshaft, all the way around. Found exactly zero,
zip, nada difference all the way around the circle. Cut a stick to where
it overhung the ridge by 1/2 mm or so, and found that the overhang was
EXACTLY the same all the way around, to the resolution of the Mark I 
eyeball.
That engine is exactly centered on the adapter plate. Bang goes the most
likely cause of shattered clutch discs.

Next measured the diameter of the ridge itself, and the diameter of the
bellhousing opening that it must fit into. They differed by less than a
millimeter-- no way the adapter could slide around inside the bellhousing.
Bang goes the second most likely reason.

Next slid the new pilot bearing onto the transmission input shaft. I've
never done this before, but I guessed that the fit should be pretty tight.
Well, it wasn't. It wasn't horribly loose, by my guessed-at standard, but
as I pushed the bearig from side to side, I could see it move slightly,
maybe around 1/2 mm from side to side. Tried to call a few listmembers
who had been foolish enough to give me their phone numbers in the past,
but they had all anticipated my whining and were nowhere to be found.
Probably working on their own VWs, or some such flimsy excuse. So, given
the time crunch I knew was coming for the next month, I put everything
together this way and buttoned it up.

Anyone know if there is a spec for this looseness? I also tried rocking
the pilot bearing right and left on the input shaft (about a vertical axis),
and found I could turn it about 10 degrees either way-- 20 degrees lock to
lock if you will.

I can see where the input shaft, given the built-in slight wobble where
it mounts in the transmission, can vibrate or bounce slightly back and
forth inside the pilot bearing when the clutch pedal is pressed in. Not
very far-- maybe half a millimeter total displacement inside the bearing.
Is it supposed to do this? Or do I have a worn input shaft on my hands?

Wheel bearings, by comparison, are not like this. Of course, they are
tapered, which pilot bearings aren't. When setting a wheel bearing, you
basically set it to *zero* play: Torque it down fairly hard to seat it
on the race, then back it all the way off and re-tighten to a very small
pressure, like 4 *inch*-ounces I believe, which is one light finger on
the end of the wrench, if you use a wrench at all. Same thing with bicycle
wheel bearings, for you old cup-and-ball types. This sets the bearing to
zero looseness, but with virtually no load.

Should a pilot bearing also have zero looseness? Mine doesn't. Since the
pilot bearing is straight rather than tapered, it would take some pretty
precise machining to get it right-- but no more precise than machining
the bearing case to press-fit into the flywheel, which this one did 
perfectly.

With no external references (i.e. I was ignorant), time running out, and
my natural laziness about lying under that d*mned bus during two beautiful
spring days, I went with the bearing and shaft as-is, and reassembled
things. Forgot to plug in 12V to the relay that provides switched power
to the choke and cooling fan, but everything else went together fairly
easily.

Fired it up, and that new clutch was smooth as silk-- how sweet! Drove
around a little, and noticed those same old vibrations around 3,000 rpm.
A hollow droning from the back of the bus, and a metallic rattling of the
shifter handle, which I've always found odd in this bus.

So the V6anagon is back on its feet again, and cruising around like
its old spunky self. And the things that made the clutch fail in 6,000
miles, are still there in full force, whatever the h*ll they are, and
I'll probably have to do it all over again.   <sigh>  I was afraid of
this as I reassembled the rearmost 600 pounds of car, since I hadn't
changed anything that could have caused the problem. Best I can say now,
is that maybe I can next pull the engine at a time and place of *my* 
choosing,
rather than 450 miles from home with six people in the car.

So, three questions:

1.) How much play should the input shaft have inside the pilot bearing?
2.) What is the minimum allowable diameter of the input shaft where it
goes into the pilot bearing?
3.) How do you replace the tranny input shaft? Trans out of the car? Open
the tranny case (shudder)? Take it to a rebuilder?

Depending on the answer to (3) above, there may be two others:

4a.) Does Kennedy make an adapter for a V6 engine into an *automatic* bus?
4b.) Anyone have a Vanagon automatic tranny they want to sell?

Thanks, friends, for all your help and contributions. I'd really like this
saga to be over. But it's good, at least, to have the V6anagon cruising
again. For now.

    _______
   /\ o o o\         Steve Maher   smaher@gi.com   75461,1717
  /o \ o o o\_______   San Diego, California
 <    >------>   o /|
  \ o/  o   /_____/o|      '80 VW V6anagon
   \/______/     |oo|        '66 Mustang Coupevertible
         |   o   |o/       '89 Son Sherwin
         |_______|/
                     http://www.lookup.com/homepages/76242/home.html

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