Like most old-school custom techniques, headlight frenching used to be a quick and dirty job. The stock headlights were installed from behind the fender and, if they were adjusted at all, the headlights had to be removed to access the adjuster screws.
Once the '52 Mercury was introduced, customizers began using its ring and bezel to sink the headlight bulbs further into the fender, but they still didn't spend much time accounting for the adjusting process. There are a few methods for adjusting the bulbs from the front with the '52-54 Merc rings and bezels, but they require the rings to be screwed in from the front side, leaving the screw heads visible.
These days, there are plenty of ways to french headlights, including quite a few varieties of kits available to complete the job. Some of these methods, including the Hagan kit featured here in Rod & Custom a while back, provide access to the adjuster screws from the front by using a removable bezel, but the look is quite modern compared to the older methods.
Here, we have presented a very simple and effective way of adjusting frenched headlights from behind the fender. This method provides a way of frenching headlights the old-school way, without sinking them back into the fender, while still maintaining a relatively simple and functional adjusting system.
We used a stock pair of GM truck rings and buckets on a '49 Chevy pickup. Of course, there are subtle differences between different car manufacturers, but the general concept and modifications can be used on most headlights of the same style.
This job is very simple. All...
This job is very simple. All you need, in addition to the headlight bucket and assembly, are two long 1/4-inch screws and un-plated hex nuts (that is assuming that most headlight assemblies have two adjusters rather than three. These GM buckets, like Ford, have two adjusters per headlight).
The first step is to completely...
The first step is to completely disassemble the headlight assembly. We removed the retainer rings and bulbs, and then turned the adjuster screws out.
The adjuster screws work against...
The adjuster screws work against the tension of (usually) one or two springs on the opposite side of the headlight bucket. Once you turn them out far enough, you can unhook them and remove the entire bulb holder.
Once the bulb holders and...
Once the bulb holders and adjusters are removed, the small captive adjuster nut can also be removed. We will replace these with hex nuts on the rear of the bucket.
In order to drill a hole for...
In order to drill a hole for the new adjuster screws, center-punch the bucket on the opposite side of the original captive adjuster nut that we just removed.
You will be able to tell if...
You will be able to tell if the punch mark is properly located by making sure it lines up with the original adjuster nut holder on the front side of the bucket (arrow).
Once you're sure the new adjuster...
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...
The new adjuster screw hole should line up with the original adjuster nut holder.
Now place the bulb 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...
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...
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...
Once the muriatic acid has set, brush and clean the bulb holder well before welding on it.
Use smaller 1/4-inch screws...
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...
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...
At this point, you can reassemble the entire headlight bucket to make sure everything fits and lines up properly.
Depending on the shape of...
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...
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...
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...
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...
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,...
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.