'86 4kq diff locks

[R Mangas]

   On both my cars (86 and 87 4kq) the difflock actuators themselves were
leaking.  The actual lock mech in the rear of the 86 was stiff from lack of
use (I now regularly cycle them locked/unlocked a couple times a week even
if not needing quattro grip).  The one tool I could not have done without
was a mityvac- you can apply vacuum to where ever you need to and the gauge
will indicate a leak condition.  If it was me, I would:

1.  verify both that the indicators are working and that the actual mechs
are free to move by locking the diffs by hand with the vehicle on
jackstands.

2.  Pull the hoses off of the nipples on the actuators (fun fun!) and
mityvac each nipple.  If you get a leaker, pull the actuator (fun fun fun!)
and either repair or replace.  I opted for repair; JB weld is your friend.
Pay close attention to which hose goes where- they're color coded.

3.  If you get actuator function in both directions with the mityvac then
you know you've a vacuum problem.  Don't fret- that's probably easiest to
deal with!  The vac hoses are old now, and often crack where they go over
nipples or hardline (the in-body lines are a harder smaller dia tube; no
maintenance necessary IME).  There is typically plenty of hose to allow you
to pull it off, nip off the bad 0.5" and replace.  Do this EVERYWHERE.  The
engine department looks like a horrible nest but go slow and it'll only take
about a half hour.

4.  If that doesn't work I'd take the switch manifold apart and apply the
mityvac to the lines to the actuators and watch your indicators; in this way
you'll be able to isolate where the problem(s) is/are.

   Sounds like a PITA, but the payoff is totally worth it.

hth,
Robert





>From: "jesse" <clerick44 at earthlink.net>
>To: <quattro at audifans.com>
>Subject: '86 4kq diff locks
>Date: Mon, 13 Jan 2003 23:55:04 -0600
>
>This is a multi-part message in MIME format.
>--
>[ Picked text/plain from multipart/alternative ]
>     With the first real snow of the season i was excited to use the diff
>locks for the first time in the 2 years i have had the car.
>     Problem, the rear diff doesn't show it's engaged, i would assume it's
>the plunger back there.  But the center lock-up worked, UNTIL i got the
>revs high.  Then the light would flicker out and *klunk* the diff would
>unlock.  Get off the throttle and it would reengage.  I am assuming it's a
>vaccuum issue.  Any suggestions for testing the lock-up mechanisms and
>related vaccuum system.  I havn't recieved my Bently manual yet (i swear
>i'll stop pestering you all so much when i do) so i have no idea where to
>start.
>
>Thank you all yet again,
>Jesse Erickson
>--


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