Thank you all for the fast help guys. I would have never thought of the oven trick...
Update 1:
Bakin' the headlight to take it apart wasn't imposible, but it was far from easy. The plastic, not to mention the screws, got quite warm after about 20 minutes on 150F (75C), but the sealant was nowhere near the release point. After another 20 minutes on 200F (93C) it started to loosen up a bit. It was still not moving as easily as I would want, but I didn't dare to heat it any more, besides it was geting too hot to hold in my hands. After some struggle on the kitchen counter (make sure you cover it with a towel or even a blanket to avoid scratches on both the light and counter) I finally managed to pry it open without causing much damage. What I found inside proved this operation worth my trouble:
- Philips screws on one of the adjuster plates were loose and the whole low beam module was moving in the housing.
- The whole headlight housing was full of black dust. The reflectors, glass, lenses and pretty much everything else was dimmed at least 30-40%. That's why all those cagers were cutting me off at night - they didn't see me because of my dim low beam! But, I digress - the source of the infamous black dust were plastic parts rubbing at each other because of the poor design, drunk assembly worker or heat deformation. In my case it was the chromed plastic reflector rubbing against the gousing in the upper left corner.
Of course, I took everything apart to the smallest screw and gave it all a "heawy pans" round in the dishwasher (yes, glass lenses and plexiglass included). I didn't want to cratch anything by wiping first.
Next step will be to put it all back together and figure out how to prevent any future black dust, loose screws and other mishaps (I don't want to go through this hassle again, you know). I also need to find out how to re-seal the headlight housing again properly and with minimum mess. Any Ideas?
Update 2:
- Used helmet visor polish to shine and clean everything up.
- Removed blockers from both lights. If this becomes a problem I will use stickers on the outside to block beam(s).
- With blockers (shades) removed lenses were a little loose in their place, especially the short beam one. Put some thin rubber stickers under the rim of the chrome ring that holds them in place.
- Put a thread locker on all internal screws. Glued ones that go into plastic.
- Put some thin felt (not rubber) sticker pads in the places where plastic parts were rubbing against each other. That will hopefully prevent future black dust accumulation.
- Put everything back together and centered the beams as much as possible before reassembly.
- After much research and experimentation decided to re-seal the housing using the Nissan headlight sealant (Part# B6553-89915 "sealer."). I was very carefull not to put too much - just enough to fill the spots where the original sealant was thin.
- Back to the oven and reassembled. This is definitely not an operation I would ever like to repeat.
