I don't know why he said 36" either. It is probably an arbitrary number he just thought was right.
The line on the wall or door, 25 feet in front of the headlights, should be the same height as the center of your headlights. Adjust (low beam) so the top of the bright part of the projection on the wall is 2" below the line. There is no adjustment for left and right on these U.S. market vehicles.

 

36" is the mark that most states use as law. He was not picking an arbitrary number. Here in MD that is the exact way we set lights for all vehicles.

Think about what you said with the,

Not every car has the same height of headlights, a Lambragini for example would be way low and a dump truck would be way high. 36" keeps all vehicles on the same plane and gives you light at 200' on the road.

 

I am not trying to argue, just trying to work out the correct way. So, lets go.
Think about what you said with the line at 36" for all headlight heights.
If a car has headlights 2 feet off the ground, they will have to point up to intersect the 36" high line on the wall. If the headlights are 4 feet high, they will have to point down to intersect the 36" line. Besides, the procedure I gave is taken from the instructions for our JK's, not a Lambragini or a dump truck.
More dialog welcome.

 

Sorry if I came off as arguing, not intended by any means.

What you say is true.

However the 25' / 36" numbers allow for all lights no matter how high or low they are mounted to project the same light at a given range. (I do not know what that is). Using the 25/36 marks it will give the lower sitting vehicles an intersecting light with oncoming traffic at a far enough distance that it will not interfere with oncoming traffic. This setup will give higher vehicles an intersecting light at a distance that is too close to oncoming traffic to affect it.

I do not know all of the logistics. I do however know that the 25/36 numbers were reached to give optimin safety and still have a usable light of 200 feet. ( the min required by MD law)

Again, this is how we are trained by the state of MD. I do know many states use the same guidlines. Your best bet is to check with your local inspection station, they will give you accurate numbers for your area.

 

I have been on Google looking for guidelines from different states and cannot find anything related to adjusting headlights. But, I have always been aware that when a garage puts their aiming machine up to a headlight, the machine is at the level of the headlight, no matter what vehicle. (I have always wondered how those things work)
And, like I said, the line at the same height as the headlight is the proper way for the JK. Do states call for something different from what the manufacturer says? I would think they have to comply with a Federal Standard.

 

I lined my headlights up according to the 25' x 36" recommendation and it worked beautifully.
Of course, I did it at midnight and I used the side of a local building because my driveway is sloped. Cops came out to check what I was doing.

 

Oh well. I guess you can't argue with success.
I'll tear that page out of the JK Service Manual. Apparently they have it all wrong, which calls into question the validity of the whole book.
I face this every day at work. I insist on fixing the aircraft by the book; supervision just wants it back in the air. When faced with signing it off themselves, they are more than happy to let me fix it by the book.

 

I know this is an old post, but come on- why didn't some one point out that the service manual deals with stock tires / un-lifted jk. I searched for this thread because I read it b4 but never adjusted the lights- now I'm going to install 2.5 BB and will need the info- 25'/36" Joe

 

I will try again.
The line on the wall must be at the level of the head lights. 36" for all vehicles is just dumb. If one's headlights are lower than that they will point upward to hit the wall at 36". If one's headlights are higher than that, they will point downward. They are supposed to point just below level.
Read the manual! The amount of lift is irrelevant.

Measure the distance between the optical center of one of the lamps being aimed (head or fog) and the floor (horizontal zero reference). Transfer this measurement to the alignment screen with a piece of tape placed horizontally to the floor. This line will be used as the lamp horizontal reference.

Due to the linear nature of the headlamp cutoff, a properly aimed low beam headlamp will project the top edge of the high intensity pattern on the alignment screen from the horizontal line to 50 millimeters (2 inches) below the horizontal line.


I'm done, now. If a 36" line is what you want, then a 36" line is what you get.

 

Sorry to revive such an old thread.

I know how to do my headlights up and down. they are adjusted after my hella e code conversion. however, I cannot figure out how to get them to adjust sideways? My lights are awesome but they are not "overlapping" which causes a "U" shaped beam of light. I have a dark spot on the road in the middle front of me, while the sides of the road are lit up....