Headlight Aiming

Another JR · December 24, 2021

The owner’s manual says see the dealer for headlight adjustment. I’m interested in adjusting mine down a little to compensate for my camper lowering the rear a couple of inches. Does anyone know if the adjusting means is easily accessible?

Supreme Pizza · December 25, 2021

3 hours ago, Another JR said:

The owner’s manual says see the dealer for headlight adjustment. I’m interested in adjusting mine down a little to compensate for my camper lowering the rear a couple of inches. Does anyone know if the adjusting means is easily accessible?

One what type of rig?

Another JR · December 25, 2021

2021 GMC 3500HD SLT (LED headlights)

Supreme Pizza · December 25, 2021

You could try adjusting the tires pressures and what not, but unless you plan to adjust your headlights every time that you put the camper on, then you would just have to live with it.

Dunn · December 25, 2021

There's a screw right on top for headlights, super easy

Gmc is easier than chevy HD

Supreme Pizza · December 25, 2021

Adjusting your headlights is not done with a screw at the top of the headlight. That is an incorrect procedure. Every year, many many people die because they were blinded by oncoming headlights that were misaligned. This is very common: "I could not see, so I ran off the road, and now my husband/wife/kid is dead..." If you do not know EXACTLY how to adjust your headlights, then you should not attempt to do so without obtaining the proper procedure. Take it to a shop and pay them the $50 to do it properly. Better safe than sorry.

Other people will say this is dumb, and you can adjust them yourself.

In response, I say:

Edited December 25, 2021 by Supreme Pizza

Another JR · December 25, 2021

I know how to properly aim headlights - I’ve been doing it for 40 years. I just was wondering if GMC has made the adjustment method impossible for a DIY person after reading the manual. My truck is out in the barn and it’s cold, rainy, and windy out, so I was asking here rather than looking myself. The camper stays on almost all the time, so I want to adjust them for that load. I have no problem with having the headlights aimed a little low for the small amount of unloaded operation I do.

The camper weighs 1800 lb and the payload is 4054 lb, so it will be a small adjustment. However, I’ve been flashed enough times that I want to be courteous to other drivers and fix it.

gemarsh · December 25, 2021

5 hours ago, Supreme Pizza said:

Adjusting your headlights is not done with a screw at the top of the headlight. That is an incorrect procedure. Every year, many many people die because they were blinded by oncoming headlights that were misaligned. This is very common: "I could not see, so I ran off the road, and now my husband/wife/kid is dead..." If you do not know EXACTLY how to adjust your headlights, then you should not attempt to do so without obtaining the proper procedure. Take it to a shop and pay them the $50 to do it properly. Better safe than sorry.

Other people will say this is dumb, and you can adjust them yourself.

In response, I say:

With that much knowledge, you ain't gonna answer the OP question? You are telling him to flatten his tires?

Some of us turn wrenches, know up from down, and would like to know where the adjustment takes place, setting in the house.

OP, I will look today for you, 55° and sunny here the weatherman says for today.

gemarsh · December 25, 2021

16 hours ago, Another JR said:

The owner’s manual says see the dealer for headlight adjustment. I’m interested in adjusting mine down a little to compensate for my camper lowering the rear a couple of inches. Does anyone know if the adjusting means is easily accessible?

Dunn was spot on, answering your question, if'n the 25/3500's are the same as 1500's.

Skip to minute 5:15...

Another JR · December 25, 2021

3 hours ago, gemarsh said:

With that much knowledge, you ain't gonna answer the OP question? You are telling him to flatten his tires?

Some of us turn wrenches, know up from down, and would like to know where the adjustment takes place, setting in the house.

OP, I will look today for you, 55° and sunny here the weatherman says for today.

Thanks for the help, gemarsh. Use of tire pressure to aim headlights on a truck was a new one for me, too.

cinci5 · December 25, 2021

My 15 2500HD has the screws did it in driveway at night.

l changed to HID setup so it was critical for height.
Bright as heck and very definitive line to see.
Also Morimito fogs needed adjustment they also have screws.

Another JR · January 18, 2022

I finally looked at the back of the headlight assembly and easily found the vertical adjustment feature. You need either a long #1 phillips screwdriver or a long (about 5 inch long) 6 mm hex wrench. The mechanism turns easily. I did not readily see the horizontal adjustment feature. I didn’t look for it because I am only compensating for leveling my truck by installing a pop up slide-in camper.