Fixing a BMW E39 lazy eye

My mid-nineties BMW 525 TDS is a lovely car, but it came with a classic E39 problem: The left headlight reflector was loose and just pointed downwards and rattled when I bought it. I googled around to check the procedure and found a couple of good descriptions of the work needed, but I’d like to add to them, since they made it unnecessarily complicated.

Parts needed

Flimsy plasticky things that tend to break

Adjustment screws (set of two): BMW Part Number 63120027924

Tools

  • 8 mm hex head bit
  • Torx T15 bit
  • 8 mm Allen tool
  • Flat-head screwdriver (a couple of sizes might be good)
  • Possibly a pair of long pliers

Step-by-step How-To

  • Loosen cables to lightbulbs and height adjustment servo. You might just choose to remove the light bulbs already and leave them hanging in the cables, since that has to be done anyway.
  • Remove the four 8 mm hex head bolts holding the headlight in place and remove headlight gently, starting from the grille.
  • Place headlight on soft working area (I used a towel on a table) and remove the light bulbs if you didn’t already.
  • Remove the high and low beam brackets and the bellows around them (they use three T15 screws each).
  • With a flat head screwdriver, remove the plastic panel below the protective glass pane, and then continue to pry open each of the clips holding the back end of the headlight mount to the front end. On the side towards the turn indicator, there’s a slightly larger plastic clip. You don’t have to touch the turn indicator part at all for this operation, so just leave it closed.
  • Remove the back end. One or both of the adjustment screws in the upper part of the reflector housing will be broken. If it’s both, you just saved yourself some work, otherwise you have to pop the reflector off the ball on the end of the remaining screw. Remember: The screws are cheap. The receiving end on the reflector isn’t – you’ll probably have to buy a new reflector if you break this part…
  • Tilt the reflector forward and pull it upwards. It will slide off the nylon part on the lower (adjustment servo) screw. Other descriptions indicate a need to pull the reflector off the ball end here, but that’s just a useless thing that actually might break an important part of the reflector, so just do it the easy way. On Xeon equipped headlights, you do need to pip the reflector set off the adjustment servo screw – there’s no room to slide it off.
  • If possible, loosen the adjustment screws. Use an Allen tool and use the adjustment points at the back of the housing. These screws are threaded the “wrong” way around, so turn them clockwise to loosen the screws inside.  If the screws are broken, just use pliers to gently pull them out, and make sure no plastic splinters are left behind. Oh, and count the number of turns. It makes life a lot easier later on…

    No threads. No problem.
  • You’ll need to thread the new adjustment screws, so put some soap or other lube on the hole and start screwing counter-clockwise. If you found this the least bit dirty, go wash your mouth with soap and water. Just tighten it the same amount of turns as you had to loosen each screw earlier. I’d say around 30 rotations for each screw is a good number to start with if you forgot to count earlier.
  • Slide the reflector back down onto the nylon washer and snap it into place on the ball-ends of the adjustment screws.
  • Put everything back together in the same way as it was dismantled. The plastic panel under the headlight glass has a small hook on the outer end. Make sure it snaps into place in the side panel of the car.
  • Take care when changing light bulbs from now on – the plastic in the adjustment screws gets extremely brittle with the constant changes in temperature that it has to endure.