Date:         Mon, 1 Mar 2010 21:20:27 -0800
Reply-To:     Robert Fisher <garciasghostvw@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Robert Fisher <garciasghostvw@GMAIL.COM>
Subject:      Auto Tranny R&R&R completed (finally)
Content-Type: text/plain; charset="US-ASCII"

Long, but with a question at the end; if anyone wants to take a crack at it
without reading this whole thing just skip down.



So I finally got the damn tranny working. This tranny that I rebuilt is the
one that failed on me several years ago (at about 140K miles according to
the records I have) and led to me mothballing the van until last year. I
pulled the full transaxle out of an '86 I acquired and swapped it in, and
that tranny failed in early December at about 120K total miles, so I pulled
the trans section from the "old" one and set to rebuilding it with parts I
already had on hand for it. From what I understand about these trannys those
are low miles for failure, but I know at least part of what led to each of
those breakdowns; in other words they didn't fail due to some inherent
weakness but rather due to other problems.



 When I tore it down I found that the diaphragm spring in the forward clutch
was in upside down (I would guess from an earlier rebuild). I have no idea
how it ever worked that way, unless they just drove it until it "broke"
in... I'm guessing that in part it led to its early failure.



When I got it back in (I had just pulled the auto section) I found that I
had forward gears in all gears, including Park. Reverse tried to pull, but I
could tell it was fighting the forward drive at the same time. I thought at
first that it might be some issue with the valve body, which I had cleaned
back when and had not put any miles on since, but since I knew that some
contaminated fluid was still left in the TC I pulled the valve body and went
through it again. I could see some sediment but nothing excessive or
alarming. I remembered that at least one valve had seemed somewhat stiff to
me so I really went over them until they moved well and freely. I noticed
that the separation plate was fairly worn, but as I couldn't do anything
about it I went ahead and put the valve body back in. No joy.



I talked to Ken at German Transaxle about my problems and what I'd done. He
was helpful and informative, and didn't mind talking to me; I called a
little while before closing so as not to interrupt his day any more than
necessary. We went over various failure scenarios and he told me about their
services. Basically my options with them ranged from buying an entire
rebuilt tranny section (sans diff), with or without TC (no warranty without
it) to having my valve body reconditioned (including the separation plate)
or alternately just buying one that had already been reconditioned (cores
required in all cases).



I was out working that night, and since there isn't much to do but think
while you're pressure washing at two in the morning, I was mulling over the
conversation and began to think about some of what we'd discussed about "end
play", which has to be checked and possibly adjusted at several points
during the rebuild. I got to wondering if the thing was just mechanically
bound up somehow, which was not allowing the various clutch packs to release
(which is why I posted the question about shim measurements the other day).



So out it comes again. I pulled everything out down to the direct/reverse
clutch without seeing anything obvious, and on sort of a whim I tried to
turn the internals on the forward clutch by hand and lo but they wouldn't
budge. I broke it down on my desk and found my problem.



The night I rebuilt the forward clutch pack I had a bad cold and I was
exhausted for various reasons, mostly, as usual, related to trying to run a
night-time business and leading a normal life. I'm afraid I wouldn't make a
very good Batman; On the other hand he's a billionaire, so maybe that helps.
At any rate I was literally sick and tired. I was following my breakdown
pictures in reverse as I reassembled the tranny, and when I was doing the
forward clutch I remembered the diaphragm spring being inverted, and as I
picked it up I told myself "convex side down", and damned if I didn't just
look at the picture and put the friggin' thing right back in the wrong way.
Never underestimate the power of the visual.



It took all of five minutes (maybe) to straighten that out- plus the great
fun of removing and replacing the thing. Fortunately there didn't appear to
be any undue wear from the misadventure.



Now it works great (except for one thing); it's kind of amazing how much
more smoothly the thing shifts. It shifts from 1st to 2nd at 15mph now
instead of 17, and it shifts from 2nd at about 32 instead of 27. 65mph is
right at 4K, and acceleration is smooth and quicker (if one can say that
about a Vanagon) than it was.



The problem now is that it's making a weird noise- something sort of between
a scrape and a swoosh. I haven't had the chance to get under it again and
listen with the stethoscope. It's loud but not horribly so, and it doesn't
sound from the side of the van much like a mechanical interference noise. It
doesn't happen in drive, but only in P, R and N, and only then at rpms below
2600. I'm not sure what to think of it, so any suggestions will be
appreciated. I'll get under it tomorrow and see what I can learn then.



Cya,

Robert