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?