A lot of sports car enthusiasts love the classical Porsche with its air cooled design. When this version was initially released in the United States it used very specific headlamps thanks to the DOT regulations which mandated sealed beam lamps, but the good news is that you can use the guide below to easily upgrade them to modern H4 headlamps that use halogen bulbs.
Tools You’ll Need
Step One: Remove the Headlamp Outer Ring
To extract the headlamp outer ring you must first remove its retaining screw which can be found near the bottom of its headlamp. Once the screw has been removed, lift its ring off through rotating its bottom edge then pulling its ring upward.
Step Two: Remove the Headlamp Housing and Internal Ring
If you’re working with American spec headlamps, whether H4 or sealed beam, you will notice that the roundish headlamp housing is secured in position with an internal ring. Gently extract the miniature screws which hold the internal ring in position. For the 911SC you’ll see three miniature screws that are evenly spaced. Avoid stripping them.
Step Three: Replace the Headlamp Bulb and Housing
If you only need to replace the existing seal beamed headlamps, just swap in your new seal beam. But if you intend to upgrade to Euro or American spec H4 headlamps be sure to install the newer H4 bulb into its H4 housing back. Screw its bulb into the housing using spring clips. While doing this, assess the rubber seal’s condition, as it surrounds the headlamp bucket opening. If you find it’s damaged, you’ll want to replace it.
Step Four: Reinstall the Headlamp Housings
Reattach the electric plug inside the bulb’s back then put the headlamp housing inside its retaining bracket. If you plan to reinstall American style H4s or seal beams, make sure its indentations in the headlamp back housing align with headlamp retaining bracket notches to ensure its headlamps are within the proper orientation.
You’ll also need to reinstall its internal ring so the headlamp housing is secure. Reinstall the external ring through hanging it from the headlamp opening’s top edge, and then rotate downward and put the ring within position. Illuminate it using your flashlight to verify the external ring hole aligns with its threaded retain screw hole near the bottom. Press firmly downward above the external ring while threading the retain screw manually, and carefully tighten it.
When installing headlamp housings which are Euro spec, there won’t be a headlamp retaining bracket or internal ring. What you want to do instead is hang the whole headlamp assembly in the headlamp’s opening upper edge, then rotate downward then seat its assembly within place.
Step Five: Re-aim the Headlamps
If you upgraded to American style H4 headlamps or replaced sealed beams, verify that its aiming screws and retaining bracket haven’t been disturbed. You want their aiming positions to be identical to how they were originally. When working with vintage Porsches, it is also advised to take the vehicle to a local service or gas station where a technician can review and adjust the headlamps as needed.