(Audi) Timebomb Ticking?

[Timothy C Salazar II <tsal2@juno.com>]

Hey All,

I've got a really annoying ticking sound coming from my 4ksq.  It seems
to be emanating from the back of the engine, (closest to the firewall),
probably the tranny.  Anyway, it starts up after I've gotten the car wet
by driving it through a puddle or washing it.  Then it becomes
intermittant.  It ticks faster with the throttle, not by the movement of
the car.  Any ideas?  I'm taking a wild guess and thinking that the
quattro system isn't disengaging properly somewhere, or something.  But
that's just me using the `ol "8-Ball of Car Mechanics" as a guide.  Also,
how much tranny fluid goes in the center & rear diffs?  And how/where do
I put it in???  I'm planning on using Redline 75w90;  does that jive? 
TIA!

Love, Like, or Just Plain Tolerate,

Timothy

`85 4ksq
`86 CGT (R.I.P.)
`82 Coupe (R.I.P.)