1952 Mercury French Headlight Adjustments - A New Trick For The Old French

Once you're sure the new adjuster screw hole is properly located, drill a 5/16 hole. This will allow some play for the 1/4-inch adjuster screws.

The new adjuster screw hole should line up with the original adjuster nut holder.

Now place the bulb holder in its proper location on the bucket and make sure the new adjuster holes line up with the notches in the bulb holder for the original adjuster screws. If these are slightly off, file the new adjuster holes in the bucket.

Since we are using 1/4-inch screws to adjust the headlights, we have to file the original adjuster notches to accommodate the screws. File these until the screw fits loosely in the notch.

Since we need to weld new adjuster nuts onto the original bulb holder, we have to prepare the surface for a proper weld. Unlike bead-blasting, muriatic acid dissolves zinc plating rapidly. Use gloves and a respirator if you don't have a hazmat suit handy.

Once the muriatic acid has set, brush and clean the bulb holder well before welding on it.

Use smaller 1/4-inch screws to hold the hex nuts in place on the bulb holder. Since the adjuster screws will be installed from behind the bucket, we welded the nuts to the front of the bulb holders.

No need to go crazy with the welding. A small stitch is all you need to hold the nuts in place.

At this point, you can reassemble the entire headlight bucket to make sure everything fits and lines up properly.

Depending on the shape of your headlight bucket, you will need around 2-inch-long screws for your new adjusters. Here, we made sure that each of the adjuster screws was perfectly lined up and straight in the bucket.

This is what you will see from the back side of the fender. We used button-head Allen screws, but any style screw will work, including standard hex-head bolts. The washers account for any slop in the bucket hole and ensure a smooth turn of the adjuster screws.

From the front, you can see that the adjuster screws don't stick out any farther than the headlight bulb retainer screw heads. This is important for clearance if you're using a Merc-style bezel to set the headlight back in the fender.

With the bucket mounted in the fender, you can see that besides the fact that you will have to reach up under the fender, this method requires no disassembly; just turn the new adjusters in or out for proper adjustment.

Our headlight ring isn't yet welded to the fender, but you can see here that our headlights will be frenched the early way, without the bulb being recessed into the fender at all.

Just for demonstration purposes, this shows an alternative method of recessing the headlight further without having to install a trim bezel from the front of the headlight opening. This eliminates visible screw heads in the bezel.