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How to adjust GMC Yukon Denali Headlights?

lethanh37lethanh37 Member Posts: 1
edited March 2014 in GMC
I know how to adjust the vertical (up and down) adjusters

I need help finding how to adjust the horizontal (side to side) adjusters

Please let me know



  • alicia6alicia6 Member Posts: 1
    Need help on how to adjust the headlights up and down. Help is greatly appreciated!
  • bravomachadobravomachado Member Posts: 2
    Did you ever find out how, and if so can you tell me?
  • nofordsnofords Member Posts: 2
    My 2008 yukon has the worst headflights I have had in years. They are so low on High beam I seldom get flashed if i leave them on bright on a divided highway. How and where is the adjustment screw to raise them? Also what hieght and at what distance do I adjust them at night against a wall / Thank you.. Any other suggestions?If a brighter bulb is suggested what is the most I can go with out jepordizing warranty or causing an overheat or fire etc.
  • rshtrsht Member Posts: 277
    Hi nofords, to adjust your 08 Yukon's headlamp aim, being its still under warranty your dealership service department should adjust them for you; but if you really rather do that yourself, below is a brief list of steps. Basically:
    1. make sure all your tires are properly inflated...
    2. park on a level surface with no extra load in the back of your Yukon
    3. your vehicle should be 90 degrees to the wall that you are using to adjust your headlamps aim (If your Yukon is equipped with auto leveling system, you probably want to keep the engine running to maintain the ride height; ...come to think of it, keep the engine running anyway to avoid running down the battery...)
    4. the distance between the plastic face/lens of each headlamps (there is a tinny circle marking or called "aim dot" on each side of the lens) should be 25ft away from the vertical wall (the right way to measure the 25ft is first mark the floor where its vertically down from each headlamp's aim dot, then from each mark measure 25ft straight out to the wall)
    5. You may want to draw a horizontal reference line across the wall at the same height as your vehicle's headlamp's aim dot, then two vertical reference lines at the same distance between your headlamps (left-aim dot to right-aim dot)
    6. Turn on the low beam for the aim adjustment, basically looking at the wall to verify that the top of the light cut-off projected on the wall is with +/- 2 inches of the horizontal reference line (you may want to block the light projection from the other headlamp to only see the one you are working on - **** NOTE: DO NOT PUT a towel directly over the headlamp as that will cause over heating and damage to the headlamp unit ******)
    BTW, to adjust the headlamp vertical aim, raise the hood, on top of each headlamp unit you should see a male star screw in silver color (some call it torx screw); Adjust the screw left/right for each headlamp as needed for proper aim height. Good Luck!!

    Oh, aftermarket bulbs... I think 08 Yukon also uses the H13 (9008) bulbs; standard brightness of these bulbs are around 3100K. I am sure there are many brands out there (Hella, Luminics, NOKYA...), my personal choice is the one from PIAA (Xtrem e White Plus @ 4000K, otherwise the less expensive from Sylvania (Silver Star @ 4000K, Ultra if they have the H13 Bulbs @ 4100K). Per my experience, the PIAA bulbs although are more costly, they seem to last much longer, especially if your Yukon has the DRL. By the way, some states have strict laws around how bright & color one can use on their vehicles, that is why I only mentioned the 4000K as they are brighter than standard halogen and still legal. Hope this helps...
  • nofordsnofords Member Posts: 2
    I will give this a try .I wanted to know what the horizontall hieght on the line would or should be on High position with headlights. Thats the distance call it from ground to roughly centre of the beam on the wall.Thanks again.
  • rshtrsht Member Posts: 277
    FYI, for my 07 Denali with the engine running (auto-leveling running), it measured from the ground to the aim dot at about 35.75 inches (for the Horizontal line).
  • rickg52rickg52 Member Posts: 1
    I agree, My 08 Yukon has the worse headlights I have had on any of my recent vehicles. I just installed Silverstars and got some improvement. Two more years until I can trade it in. Definatly will get HID's on my next one! Anyone that got better results than Silver stars please post.
  • rshtrsht Member Posts: 277
    I have had Silverstars ultra before; but they don't last very long, plus they don't offer H13/9008s today. I have been using the PIAA Xtrem White Plus bulbs, they seem to last quite a lot longer and in my opinion better illumination than the Silverstar Ultra (both at 4000K)... The Silverstar Ultra sure costs less than the PIAA though.
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