Date: Sun, 12 Sep 2010 09:42:49 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: semi-urgent auto transmission question
In-Reply-To: <4c8bbee4.0663640a.2fc7.ffffc9c9@mx.google.com>
Content-Type: text/plain; charset="us-ascii"
The symptom you describe is most likely a bad piston on the forward clutch
pack or broken rings on the pump housing for the direct/reverse clutch.
Where all the pistons replaced? Sometimes new ones do fail. These are not
part of the typical overhaul kits. Also a worn or improperly shimmed clutch
pack can also cause a problem.
The "pressure Plate" for this clutch pack came in different thicknesses from
6 to 7.2mm. Depending on the clutches and steel plates supplied this needs
to be changed. Sometimes the new stuff is thin enough I can go to the 6mm
plate and get another set clutch and steel plate in there.
If it is not right you need to get it back to the shop ASAP. Something is
wrong and continued operation could burn things up. Unnoticed slipping can
cause all sorts of damage.
Using a pressure gauge considerable diagnoses can be made without removing
the tranny and by dropping the valve body the clutches can be tested with
compressed air.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Edward Maglott
Sent: Saturday, September 11, 2010 1:40 PM
To: vanagon@GERRY.VANAGON.COM
Subject: semi-urgent auto transmission question
Got my 86 van back a week or so ago after a transmission rebuild that has
been a saga. I will cover that in more detail at some point. The short
version is that the rebuilder had the van twice, and for a long time both
times.
When I got it back a week ago the trans was working better than I've ever
experienced in a vanagon. But then I've only had basically worn out
transmissions in mine. So over the 100 miles or so I've driven it since I
got it back, it has developed a problem when cold. Today I start the van,
let it idle about a minute and back up my driveway, which is uphill. Fine.
Put it in D and hear/feel nothing. Step on the gas and it revs freely up to
about 2500 then the van takes off with a thud. For about the first block,
it felt like it was maybe slipping or was in 2nd gear instead of 1st. After
that it drove normally, but the shift points seemed a little lower than
before.
I think this symptom has to do with the trans not properly developing
pressure when cold? I've had the slipping in R when cold symptom before
this rebuild so I'm a little surprised it went up the driveway so well in R
and then didn't engage D.
Checking the fluid level, it seems a tiny bit high. Probably about 1/8"
above the top mark based on checking it hot, many times, and parked on
different "level looking" places to try to get a good reading. Could this
be a factor?
I was planning on taking a trip for about a week in the next few days.
Probably 1000 miles or less. I can deal with the symptoms I have now but
don't know if it will get worse or damage something inside worse. Opinions?
Edward