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.