Headlight Aiming

[Daddio]

Here's an interesting thread I heard on 'another' forum that I'm submitting here for your comments / debate.
An experienced classic car importer in Australia says, as a matter of course, he replaces all headlight lamps on North American cars (specifically 1950/60/70's Cadillacs, but other NA cars should apply) with locally sourced lamps.

He claims this is necessary to allow proper aiming of the headlights for driving on the left hand side of the road. He says he has a bin full of working NA headlights that are useless / potentially dangerous.
I would have thought he could have adjusted the beam by using standard aiming methods without replacing the lamps.
Can anyone verify this? Are there any Commonwealth subscribers on this forum with more knowledge?

[54vicky]

why not switch the lights from side to side?sounds like he imports more than old cars.

[Hot Rod Reverend]

I don't recall anything remotely like that in the Fomoco shop manuals, the procedure for adjusting headlights is pretty straightforward. How would it make any difference concerning left hand drive or right hand drive? what about traveling down one way streets (which both parts of the world have by the way). I would assume that everyone knows that headlights for these vehicles are sold individually with no indication of a particular side of the car.

If what this man says is true, then there has to be documented evidence by headlamp companies, and I would assume by manufacturers as well... odd stuff.

[KULTULZ]

I'm glad I was wearing my hip boots on this one. No.1, all sealed beams are off-shore (CHINA).

If there was actually an HDL aim problem with the real world and those that drive on the left, it would be in the HDL buckets, i.e.. harder to aim (adjust) the lamps further left than further right (one bucket - two adjusting screws).

[Alaska Jim]

It does sound like B.S. to me. another way to make money for someone.

[dmsfrr]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by Daddio

Here's an interesting thread I heard on 'another' forum that I'm submitting here for your comments / debate.
An experienced classic car importer in Australia says, as a matter of course, he replaces all headlight lamps on North American cars ...

He claims this is necessary to allow proper aiming of the headlights for driving on the left hand side of the road. He says he has a bin full of working NA headlights that are useless / potentially dangerous.
I would have thought he could have adjusted the beam by using standard aiming methods without replacing the lamps.
Can anyone verify this? ...

The short answer is Yes, right-hand / left-hand drive headlights are a real thing.

The next time your car is facing a wall at night with the headlights on look at the shape of the field of light. Older headlights are just an oval blob of light. As lens and reflector technology improved the beam of light from each headlight became off-set to your own side of the road, slightly reducing the area of light that could interfere with oncoming drivers without diminishing the light on your own side of the road.

Some modern headlights on low beam have a slightly wider beam with a sharp horizontal cutoff that can function nearly as well as actual fog lights. They also don't shine as much into the rear-view mirrors of cars in front of you while still illuminating the right-hand side of the road.

Image below, a quick sketch with rough examples of some 'drive on the right' patterns of a headlight.

[51504bat]

When I was into MG's I had a right hand drive 1950 TD. When I was looking for headlights for it I found out that there RH drive and LH drive headlights. So there are differences between RH and LH headlights but I'm not exactly sure what they are.

[paul2748]

I would guess it's how the reflector is aimed - probably more to the shoulder and not to the center of the road

[CrownVic55]

When my son was stationed in England, he had a couple of English cars. When we went over and we drove to France, took the Chunnel, he had to get some stickers and put on the headlights to keep the light from being too far to the left side. Pulled them off when back in England.

[fordor41]

saw a show on tv from England and they had to change the headlights on a US built car to be legal in UK for left side driving

[KULTULZ]

Read This - https://www.autobulbsdirect.co.uk/bl...ght-in-europe/

Driving a UK car on the Continent. It is a matter of adjustment... unless, you have AERO HDLS that cannot be adjusted. I am still thinking seal beam.

[Alaska Jim]

Well, I stand corrected. I never knew this, and I have lived in Japan for 6 years, and traveled to several south east Asia countries. Guess I never really noticed. It is not the first time I have been wrong. sorry.--- Jim

[KULTULZ]

Not a big deal Jim.

It is simply aim, not so much the actual beams even on AERO (and I was thinking only seal-beam at first).

I am sure most EURO manufacturers provide the new lamps with both adjustments available. The old seal beams, you could just swap headlamp buckets hopefully.

It is all in the proper alignment as to which side of the road you drive on.

[50fordcoupeman]

I think it is because they are driving upside down down there!!!

[Daddio]

>> I think it is because they are driving upside down down there!!! <<


HA! that's what he says about us.

[5851a]

I thought it was in the cutting of the glass lens on older sealed beams, like the example dmsfrr gave, more light towards to ditch side. Lamps must have a dot marking on them here. Could be a stickler if your running European lamps and get in a accident.

[KULTULZ]

Originally Posted by 5851a

I thought it was in the cutting of the glass lens on older sealed beams, like the example dmsfrr gave, more light towards to ditch side.

That was what got my panties in a wad. I have been hanging here so long that I forgot entirely of AERO HDLS.

It is the ADJ and the ability to adjust to regulations, not the actual HDL. Per the article, some EURO manufactures allow either R or L ADJ, others don't ($$$). Then again, the Asian market may be even more different than Europe.

Definitely not my forte' (Fr.).

[KULTULZ]

Below is an ILL from a 1956 Sales Brochure. It shows how HDL are adjusted so as not to interfere with oncoming traffic.

Naturally, the aiming has to be reversed in those countries that drive on the wrong side of the road-

[dmsfrr]

Originally Posted by KULTULZ

Below is an ILL from a 1956 Sales Brochure. It shows how HDL are adjusted so as not to interfere with oncoming traffic.

Naturally, the aiming has to be reversed in those countries that drive on the wrong side of the road-

Well almost...
It's not just the aiming. Each headlight bulb / headlight assemby built for cars in left vs. right-hand drive countries is made to create a field of light that is reversed left to right. It's the design of the individual reflector and lens bulb assembly.
This accounts for the comments made by Daddio, CrownVic55 and fordor41 above.

[KULTULZ]

Originally Posted by dmsfrr

Well almost...

It's not just the aiming. Each headlight bulb / headlight assemby built for cars in left vs. right-hand drive countries is made to create a field of light that is reversed left to right. It's the design of the individual reflector and lens bulb assembly.

Your point is valid, but ...

Did you read the TECH ARTICLE I posted?

What you show is a later design progression and yes that particular design is side dedicated. But there are/were other system used. I have no wish to chase the details as why would I care? I have no immediate plans to drive through the CHANNEL TUNNEL anytime soon.