Re: differential locks

[steveb@falcon.kla.com (Steven Buchholz)]

> 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? It appears 
> the only changes necessary are a new (i.e. late model 4000Q) vacuum switch and 
> double the number of plastic vacuum lines to the actuators. Is the swap a good 
> idea? Are there conditions where the center-only lock would come in handy?
> 
Yes, I did the upgrade years ago.  It is as simple as obtaining the three 
position vacuum switch and installing a couple of extra vacuum lines.  I 
was being facetious when I said simple ... the switch goes in really easily,
I had the interior out of the car ... stripped down to the carpet, and it 
was still a bit of work routing the lines.  I also seem to recall that there
was a large rubber diaphragm seal under the fuel tank that I bought to use,
but ended up not doing so because I'd have to mess with all of the fuel tank
lines.  I guess that brings up another issue, if you haven't replaced your 
fuel lines recently you might want to do so while you do the upgrade.  If 
you went this way I think the toughest thing is trying to get the vacuum 
lines to run the right way between the gas tank and the sheet metal behind 
the seat.  You could then do the diaphragm seal correctly as well.  You 
might want to crawl under the car to see what I'm talking about.  

Does having the center diff lock help?  Honestly, in the kind of driving 
I have to do here in CA I could probably do without the locks altogether.
The one thing that you notice is that the center diff is pretty innocuous 
except during moderate turns.  When the rear diff is locked you know it!

Have fun!
Steve Buchholz
s_buchho@kla.com
San Jose, CA (USA)