If you’re illuminating more of the hedgerow than the road, it is safe to assume that your classic’s headlamps need adjusting. Likewise if drivers coming the other way are flashing their own lights at you.
Although alignment shouldn’t need to be part of your regular maintenance, it is worth checking occasionally.
The assembly can loosen and shift or the suspension can ‘settle’, but the time that you’re most likely to do it is when you’ve replaced a headlight.
The example shown here uses the Lucas sealed-beam headlight assembly that was for so long ubiquitous on many British cars. New units had been fitted, so we took the opportunity to check the alignment.
This process is easy enough, but you need to be particularly careful about how the car is set up in relation to the wall or surface that you’re using, and also how precisely you position the relevant marks on that surface.
Check and check again before you start. It’s no good adjusting the lights if the marks that you are aiming for are miles out to begin with.
One trick we stumbled across while carrying out this job was that taking ‘before’ and ‘after’ photographs can help you see just how much the beam has moved. Sometimes, when we didn’t think it had moved much, a quick look at the photographs soon proved us wrong.
If you can, set up a camera on a tripod and keep it in the same position for both pictures. This will be especially useful if, like us, you’re doing the work under cover but in daylight, and the headlights aren’t showing up as much as they would do if you were working at night.
STEP 1: ON THE LEVEL
Find a level piece of ground facing an uncluttered wall. Make sure that the tyre pressures are correct all round because this can have an influence on how the car sits.
Gently ‘bounce’ the front and rear suspension to make sure that it settles properly, and check that there is nothing heavy in the boot.
STEP 2: SETTING THE DISTANCE
We were working from an old Scimitar workshop manual, which recommended that the car was 10ft from the wall.
Ensure that the car is correctly aligned, aiming directly at the wall rather than being at an angle. It might be worth roping in a helper – it took us a few attempts to get it right.
STEP 3: MARKING THE WALL
You need three vertical reference points: one opposite the centre line of the car, and one opposite each headlamp.
We did this after positioning the car and found it needed careful checking; another way would be to bring the car up to the wall, position the tape, then set the car to the required distance.
STEP 4: HEIGHT OF THE LIGHT
Measure the distance from the ground to the centre of the headlight. This gives you another indication of how level the car is – the measurement should be the same left and right.
On the wall, mark this height as a horizontal line. We’ve used masking tape, which shows up better than chalk.
STEP 5: SET THE DIPPED BEAM
Start with dipped beam and do each side in turn, covering the opposite side so that you can see more clearly where the light is falling.
On dipped beam, you want the top of the main area of light to be touching the horizontal line and falling just inside the vertical marks – as demonstrated here.
STEP 6: MAKING ADJUSTMENTS
On these sealed-beam units, there were two adjustment screws, one at the top-right and one bottom-left. The Scimitar’s adjusters featured a plastic block just behind the screw-head that needed to be held while the screw was turned.
Once you’ve adjusted it, cover that side and repeat for the other light.
STEP 7: AIMING LEFT AND LOW
Now do the main beam. Cover one side while you work on the other.
This time, you want the centre of the light area to shine on the point where the horizontal tape intersects the outer vertical tape.
The photo shows that, before adjustment, these lights were pointing much too far to the left.
STEP 8: STRAIGHT AHEAD
A few seconds later, we’d brought the beam across so that it was closer to the intersection.
With the adjusting screws, one should control vertical movement and the other horizontal, but we found that each seemed to do a bit of both, so we needed to move between the two to get it right.