I am assuming the switch installed was my old one.  But like I say, if you move the plunger on that switch only .025 - .035, that's enough to trigger the switch.  Meanwhile, the total plunger travel available is more like .200".  If I were designing it, I would put the contact point about a third to midway of available travel.  Like most plunger switches.  Gives enough latitude for tolerances.  I suppose for the fun of it I could keep experimenting with adding shim washers until it's "just right" in all 4 gears + Reverse.

    On Tuesday, March 29, 2022, 04:43:26 PM PDT, Jim. Felder <jim.felder@gmail.com> wrote:  
 
 Is it the same switch or a new switch? Apparently there were a lot of
variety among Vanagon switches, and sometimes shops do not get it right. It
pays to check that carefully.

Jim

On Tue, Mar 29, 2022 at 5:34 PM Richard Koerner <rjkinpb@sbcglobal.net>
wrote:

> On my 4 speed '85 Vanagon, I recently had the transmission rebuilt; the
> way we did this was NOT to use my existing transmission; instead, my
> mechanic had a transmission rebuilt from some other guy's Vanagon.  This
> allowed us to do a one-day exchange....old transmission out, fresh
> transmission in, and my old transmission will be used by next customer.  My
> mechanic has done this numerous times; the local re-builder he uses has an
> excellent track record.
>
> The problem is the Reverse Light Switch.  It has a "hair
> trigger"...meaning, you barely touch the plunger and the reverse lights
> activate.  I have tried numerous iterations of washers & thin shims to
> solve the problem; I am assuming my switch is my original one, transferred
> over.  At first, I thought I had it solved with the proper combination of
> shims to move switch away from transmission a tiny bit, but the problem is
> back.  Reverse lights come on in all gears.  If I totally remove the switch
> from tranny but still electrically hooked up, it's fine; but the moment I
> barely touch the plunger of the switch, lights come on.  Seems way too
> sensitive.
>
> I am suspecting a bad switch.  Something funky happening internally.
> Wondering if you guys have any experience with this issue?
>