Date: Tue, 20 Jul 1999 17:19:17 -0300
Reply-To: Malcolm Stebbins <Malcolm.Stebbins@MSVU.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Malcolm Stebbins <Malcolm.Stebbins@MSVU.CA>
Subject: Results of the Diff Lock activator discussion
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First of all, my thanks to the three of you who responded to my question
regarding the use of a door/trunk lock to activate the syncro's rear diff-lock.
Your answers/suggestions/solutions are below. Eric and Tim can "p-mail it
out" as to whether a soleniod will or will not work. As for me, I like Tim's &
Eric's (2nd) idea of a cable (see below). I assume Tim's idea could be
modified in several ways to work with the existing housing for the Diff-lock
activator. Also with the cable, there is a slot in the cable knob (up at the
dash) so that it could be slotted down in a U holder to keep the pressure on
the spring back at the rear diff, we could even use the intention in the
existing front knob shaft.
Tim, as you and I close, if you ever get around to 'making one' I'd love to
come up for the weekend and participate. Malcolm S
So here are your-all's comments.++++++++++++++++++++++++++<bold><color><param>0000,0000,8000</param><FontFamily><param>Times New Roman</param><bigger><bigger>
</bold></color><FontFamily><param>Arial</param><smaller><smaller>Eric <<vw4x4@fyi.net> This will not work for 2 reasons: the pin is spring
loaded, and the soleniod would have to keep pressure against the spring all
the time. Also the lock will only engage, if the teeth that lock are aligned.
Using vacuum will keeps pressure on until they do, unlike a momentary
solenoid.
Eric <<vw4x4@fyi.net> Just as a sent this last post I thought of something: A
cable manually operated with a lever on the dash would work.
Dr. Rainer Woitok" <<woitok@rrze.uni-erlangen.de> Why then do you
bother? A new diff lock actuator is approximately DEM 30.00 at your local
VW dealer (at least here in Germany :- ).
From: Tim Smith <<smitht@unb.ca> Have you tried to find some Jetta/Audi
door locks? It takes very very little force to engage the diff lock if the shaft is
well lubricated. And it will almost disengage by itself (fail safe I presume)
Under rear seat of the Audi's is an air pump, so push/pull is possible, just
install the pump up by the dash near the vac lines. The pump switch
direction would determine locked/unlocked. The thing is, any system that
requires constant 'on' conditions, like keeping the diff locked, will draw
current (for pump or servo) all the time. For instance ARB AirLockers require
a pump, it is common approach. The use of vacuum is best, constantly
available via engine, and the 3-balled reservoir makes sure there is enough
for a good pull always.
Installation of a stronger return spring outside the shaft on the trans would
mean good disengagement and no need to have pump/servo switched 'on'
except when actually locked, and then only likely for short durations. I don't
know if the one-sided Jetta/Audi door lock servos could simply be drilled to
accept a vac line on the opposite side of the diaphragm to allow normal
Syncro type push/pull installation. Or if they'd even need to with a return
spring in place. Worth looking into that aspect since those servos are almost
free at the junkyards. Made by VDO, in the same colours even!
Other option is a pure cable system. BUT... you can't have a 'solid' cable
from dash to locker. You need the cushion that the vac system offered, so
your cable would need to have a stiff spring with about 1" of travel worked in
somehow. Pull out and lock the cable and the spring puts some steady load
onto the locking shaft. When dog clutch is lined up after some wheelspin
then the spring would contract, pushing the lock on. Simple return spring
around shaft would do fine to unlock.
(hint: This is monospacing, ed.)<FontFamily><param>Times New Roman</param><bigger><bigger>
<FontFamily><param>Courier New</param> ^ cable, pull to lock
|---| |
--\| | /
shaft| | / spring
--/| | /
| | /
pivot| o |--------o-|
|--------------|<FontFamily><param>Arial</param><smaller><smaller>
The more I look at this the more I like it! Especially after having both locks
die part way through last winter. HTH, Tim