I'd say the cap in centre of flange.
In Bentley it says "always replace" though that likely refers to when you're
overhauling the transmission. This is on P 35.2
If it was a drive flange gasket or seal, and **I'm guessing here** if it was
failing, likely gear oil would be coming out from behind the flange but not
leaking into the CV boot.

FWIW, there is a Drive flange oil seal and O-ring shown on P35.14 for the
4spd 091

Neil.

On Nov 28, 2007 2:21 PM, Ben Cichowski <cichowski@montana.edu> wrote:

> Ok,
>
> So my head is somewhere back in 1967...I shall now, and forever refer to
> them as a CV joint/boot. ;)
>
> Anyway, I think it is definitely gear oil leaking out into the boot.
>
> Archives and some suggestions here all mention the Drive Flange Cap (blue
> plastic thing)...
>
> But I'm wondering if anyone has strong suggestions about changing out the
> Drive Axle Seal as well. Seems like a lot of extra work to go through if
> it
> is not a like candidate for the leak.
>
> Any advice on determining which one might be the problem? The Flange Cap
> or
> the Axle seal... If you read the thread below, it quite literally happened
> just as I jacked up the opposite side of the van - if that is any kind of
> clue.
>
> Thanks,
> Ben
>
> On 11/28/07 11:10 AM, "Ben Cichowski" <cichowski@montana.edu> wrote:
>
> > Thought that might be wrong...(Swing Axle that is)
> >
> > It is hard to say what kind of lube it is, but it is definitely
> �liquidy� in
> > nature � that is what got me alarmed. If if looked like CV grease, I
> > probably would have let it slide.
> >
> > So, I haven�t taken the CV�s off of a vanagon before... It sounds like,
> once
> > I take it off the tranny, that there is a plug in the center of the
> tranny.
> > And some people now glue it in with RTV? Am I on the right track? � just
> > trying to follow archive descriptions. I�ll have to take a look first to
> see
> > if I need a 12 pt key or if it is just allen � I didn�t take a close
> enough
> > look and I�m at work now.
> >
> > I guess no matter what, I need to pull the CV off the tranny and at
> least
> > inspect the plug (if not glue it in) and then clean/pack the joint
> again.
> >
> > Does it sound like I�m heading in the right direction...anyone?
> >
> > -Ben
> >
> > On 11/28/07 10:52 AM, "neil N" <musomuso@gmail.com> wrote:
> >
> >> Hi Ben.
> >>
> >> Not to alarm you but.......
> >>
> >> There is a seal in the centre of the tranny flange. A small plastic
> cap. It's
> >> might be leaking a little gear oil into the CV/boot. There should be
> info on
> >> this in archives.
> >>
> >> Or there is so much CV grease in there that as you say, jacking it up
> pushed
> >> some out.
> >>
> >> I'm pretty sure CV grease doesn't "melt" or break down to the point of
> >> draining out.
> >>
> >> But I'm sure I'll be corrected by the list if I'm wrong!
> >>
> >> ;^)
> >>
> >> On Nov 28, 2007 7:49 AM, Ben Cichowski <cichowski@montana.edu> wrote:
> >>> Hi all,
> >>>
> >>> I checked the archives - there was a good post similar to this - but
> no
> >>> follow up replies.
> >>>
> >>> I had my '88 Wolfsburg with the rear end up in the air on jack stands
> last
> >>> night to make a slave replacement easy.
> >>>
> >>> I noticed one of the Swing Axle Boots leaking a bit of of oil out on
> the
> >>> narrow end facing the wheel. Kind of squeezed out when I jacked it up
> on the
> >>> opposite side. I'm thinking it may be a result of jacking the van up
> one
> >>> side at a time to put in the stands, thus put extra pressure on the
> opposite
> >>> side.
> >>>
> >>> Has this happened to anyone else...and is it something to worry about
> - i.e.
> >>> change right away...
> >>>
> >>> ...or is it a common occurrence from jacking the vehicle up that just
> leaks
> >>> a bit only when under pressure like this, but doesn't pose much of an
> issue?
> >>>
> >>>
> >>> -Ben
> >>>
> >>> BTW, slave and clutch MC replacement took all of an hour or so -
> Thanks Ken
> >>> for the quality parts. The MC I got from you is about 3 times the
> quality of
> >>> the one I took out from the PO...and the "new" slave he had put in
> looked
> >>> like it had been through a war. Now I'm just waiting on my pressure
> bleeder
> >>> now to come in.
> >>
> >
>

-- 
Neil Nicholson. 1981 Air Cooled Westfalia -
"Jaco"  (Bustorius) http://web.mac.com/tubaneil

Engine swap beginings: http://musomuso.googlepages.com/home