'86 4kq diff locks/Propshaft

[Huw Powell]

> Recently I've red some info about all-wheel systems and it's obvious
> to me that diff locks must be  fully functional .

no, doesn't matter at all.  You lock them to get out of nasty slipperies
or in really crappy conditions.  You drive with them unlocked the rest
of the time, so a non-funtioning lock mechanism is meaningless.  Unless
is it is stuck in the "locked" position.

> I lost the ability of my power locks as well.
>
> The vacuum pump (trunk, right-hand side) is not working. Obviously
> the pump is not the source of vacuum for diff locks if rear diff lock
> is working.
>
> What is the way to test, repair or replace?
>
> Can somebody send me vacuum diagrams, electro diagrams?

for the locks, try here:

http://www.humanspeakers.com/audi/power-locks-85.htm

to get started, anyway.

> How diff locks look like?

the diff locks are little actuators on the side of the tranny (front
left, sort of) and the rear diff.

Actuated by vacuum, they also close a switch to light up your display.

The vacuum is manifold vacuum, tee'd off to a little reservoir under the
fender.  it takes a few seconds or so, and some rolling, to get them to
actuate usually.

> If a lock gets broken could it damage the transmission?

Only if , as I said, it was stuck in the locked position and driven a
lot on dry roads that way.  But you'd hear the tires scrubbing on turns
if it was.

--
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/