Re: differential locks

[dlawson@ball.com (Dave Lawson)]

>I was studying my new Bentley last night and I discovered an interesting
>upgrade in the 1984 UrQ. Before I bought my used '83 UrQ I was under the
>impression that the center and rear diffs were separately lockable, not so. 

>Has anyone made the conversion to the separately lockable diffs?

I took a slightly different approach here when I had the tranny/engine
out of my ur-quattro. Along the way I bought the diff lock setup from
a 5000TQ tranny, this included the vacum servo, heat shield and acuating
rod. This setup mounts to the transmission right above the right side axle
shaft flange. Turns out the vacum servo had a ripped boot, which is
not available as a separate part, so I removed the center diff vacum
servo from the rear diff on the ur-quattro. It turns out all these servos
are the same. I then mounted this servo on the tranny with the actuating
shaft running to the rear. Everything lines up well, but the center diff 
lock
mechanism on the tranny is designed to be used with the cable
mechanism, not an actuating rod.

I sat and scratched my head for a while, then came up with a short but
large diameter bolt, mounted this through the hole which previously held
the cable. I drilled a smaller hole through the bolt to hold the actuating 
rod.
(I appologize for the somewhat poor descriptions here, the mechanisms
are kinda tough to describe.)

In the end, everything worked fine and putting a vacum on the servo with
the ole might vac, the diff locking rod slides right into the center diff. 
We
needed to rotate the bolt/acuating rod a bit on installation, but now the
clearances are fine. I ran the vac lines to the center diff servo through 
the
firewall, like the 4000q and 5000q have them. I haven't locked the diffs
with engine vacum, haven't got around to it yet. BTW I am using the
rotary diff lock mechanism from the 4000q.

HTH
 -
Dave Lawson  dlawson@ball.com
83 ur-quattro