Plymouth Headlight Retainer Failure concerns the headlight rim retainer with three mounting tabs that can fail and release the headlight bulb.
The Headlight Retainer on Valiant, Barracuda, Belvedere, Dart, Coronet, etc is stainless steel as well as the mounting tab however the tack weld holding the tab to the rim appears to not have the same corrosion resistance as the rim and mounting tabs. Once the Highway Departments got aggressive with salt spray for winter road ice maintenance practices it looks like these welds corroded rapidly.
Inspecting your rims for degradation can be quick and revealing as you may spot one or more tabs broken away from the headlight retainer rim.
Below is the fix that I used when I found two out of three tabs broken away and the headlight loose in it’s mounting. If the third tab was to break away the headlight would drop cleanly out and hang from wires while it banged around damaging the grill and trim before potentially breaking.
Don’t let this happen to you by doing a small inspection perhaps once a year. You may have to remove some trim to get a good look at each tab.
One fix is to drill out the spot welds and use rivets with the smooth head applied to the inside of the rim. This orientation is necessary in order to barely clear the headlight when the rim is installed tightly around the glass.
Headlight Retainer Rim With Two Tabs Broken Off
Detail Of Broken Off Tab Spot Weld Corrosion
Tab Mounted In Vice Has 1/8 inch Holes Drilled At Each Spot Weld Location
Tab Is Fastened With Rivets After Drilling Rim; Rivet Heads Must Be On The Inside
Detail Of Rivets On Outside Of Rim
If you want a closer to original restoration fix it will be necessary to grind and prep both parts and in lieu of riveting use spot welding.
But do better than the factory and use a 300 series spot weld electrode for the task to fight off the corrosion and buy more resistance.