Shining a light on headlight-aiming

We've all seen it: An oncoming vehicle is hurtling toward you down the road, but something is amiss. While one headlight shines where it should, the other appears cockeyed, glancing to the side — or worse, right up into your eyes. Headlights on all vehicles are meant to aim at a fairly well defined point down the road, and there are several methods to make sure that yours are aiming where they should.

Many shops rely on special aiming equipment, while others simply use a large, flat wall marked with proper aiming targets. The wall method can produce very satisfactory — and perhaps even the best — results, and it's a handy method to know, especially for coaches that are often on the road far away from home.

The biggest problem with the wall method is that it takes a large, flat, smooth parking surface with a wall that can be used as an aiming screen. This is probably a no-brainer in Kansas or Nebraska, but it's almost impossible in mountainous, hilly or congested industrial areas.  And yes, the wall method has to be done after sunset, or at least inside of a dark building.

When to Aim Headlights

Consider aiming your headlights under the following circumstances:

  • The driver has reported poor headlight alignment on his daily vehicle condition report.
  • The vehicle is cited for poor headlight aim during a safety inspection (It is preferable to adjust headlamps before the vehicle is sent for inspection so you won't have to get them rechecked later).
  • The vehicle has had any bodywork that affects the front of the vehicle. Ditto for any suspension adjustments that involve ride height.
  • If sealed-beam type bulbs are replaced for any reason, they will need to be aligned almost immediately.

Headlamp assemblies with replaceable halogen bulbs will not usually require aiming when the bulbs are simply replaced, but it's a good idea to check aim at the first convenient opportunity.

How to Aim Headlights

First check the correct MCI maintenance manual. for information about the particular coach model on which you are working.

Headlight-adjusting hardware and brackets can vary quite a bit between different vehicles, so take a minute with the book to see what you're getting into. Some of MCI's newest coach models even feature leveling bubbles built into the lamp-housing assemblies to make vertical adjustments easier and faster.

Next, always take steps to ensure that suspensions are at normal ride height (engine running) when these adjustments are being made.

Choose the method and equipment that works best for you. If you decide to buy headlight-aiming equipment, there are many different garage-equipment suppliers that will be anxious to sell you their very finest — investigate several models, ask for demonstrations, and pick something that works well with your vehicles and with your work situation.

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