Suspension Changes and Headlight Aiming Problems

[JAJ]

Originally Posted by Macky112

hi JAJ, thank you for the reply.

I have another question, I noticed my headlights, during starting the car for the auto-level motor test, beams only move to the bottom and then back to the middle, never go past middle to the upward position.

furthermore, when I turn the manual adjustment screws for the beams counter-clock-wise, the beams does not move up.

any thoughts/comments for me?

Regards,
Michael

What you're seeing sounds normal. The motor test doesn't go up above the "normal" level, just down.

I never adjusted my headlights manually, so I don't know what's happening. Sorry I can't help you.

[blackmist222777]

Originally Posted by JAJ

When I installed my KW ClubSport suspension, I was very careful to make sure my headlight aim sensors remained undamaged and were reconnected every time I had it apart. At the rear, you have to drop the rear lower control arm to adjust the ride height, so it was apart four or five times by the time I was happy with it.

I have to admit that I've always been baffled by the posts about "my headlights are out of alignment after a suspension change". The whole point of the aim sensors is to keep the headlights at exactly the right angle, regardless of the front or rear ride heights. The system uses two sensors, a computer and a servomotor in each headlight to make sure that if either end is unusually high or low, the headlight aim is correct. It just didn't make sense to me how, if the sensors were undamaged, it could go wrong.

That was before MY headlight aim went wrong after I installed my Clubsport suspension. I did it all perfectly, and yet there the headlights were, fixed in one position, refusing to adjust. Luckily, the ride height was so close to normal that it was ok, at least for a few days.

When I had the next chance to dig into it, I jacked the car up and messed with the sensors a bit. Now, when I had an aim problem on my E39 M5, I learned a lot about the sensor system. For instance, it's fast. You can unscrew the sensor rod, move the arm with your fingers and the headlights will respond immediately, moving up and down as you move the arm. So, I put the car on the lift, pulled the left front wheel, unscrewed the sensor rod and started moving the front sensor arm. No dice. Headlights were staring straight ahead, not moving. I figured that whatever was wrong must be wrong somewhere else.

Here's how the front sensor is supposed to look when it's connected properly to the rod assembly:

Attachment 388804

As you can see, the rod is actually bent from the factory and there's only one way to put it together (that's important).

Well, if the front sensor wasn't producing any adjustment, how about the rear one? I pulled the left rear wheel off and took a look (the sensor is immediately inboard of the spring). Sure enough, the rods and ball joints were connected but something didn't look right.

After I studied it for a while, I realized that it was possible to put it together two ways - the wrong way and the right way, and mine was wrong!

Here's a picture of the the right way to put it together:

Attachment 388805

In the wrong way, you position the sensor arm (at the top, plastic with cross ribs) hanging straight down, so the H-shaped arm that links it to the bracket at the bottom reaches sideways instead of up and down. In that "wrong" position, there's no stress on the sensor (it doesn't get broken) but it doesn't work either. Hence the system locks the headlights in one place and waits for someone to repair it.

When I undid the sensor arm and moved it up (to where you see it in the picture) the headlights started to move as I moved it. System function was fully restored, and there was no need to adjust the manual headlight adjusters.

So, if you're one of the guys who've had to do a manual headlight adjustment after a spring or suspension install, check the rods and arms on the rear headlight sensor. If they don't look like the picture, get it checked out by a qualified mechanic.

[By the way, if you look at the photos on an iPad, they're the wrong way up. On my PC and Mac browsers, Chrome, IE, Safari and Firefox, they work fine. On the iPad Safari browser, they revert to the original camera orientation, which was determined by getting the lens aimed at the sensors for the pictures. The front picture was taken upside down and the rear was taken sideways. If they look strange, switch browsers.]

you sir are a life saver. thank you! fixed my issue. now i dont need to worry about getting pulled over

[JAJ]

You're welcome!

[MRG Race Co]

Wow, so glad I stumbled onto this thread tonight. I have had my lights pointed higher than normal for months now and never tried to fix it because I didn't know where to start.

This was the easiest fix ever. I went out to the garage and jacked up the car and was done in 5-10 minutes.

I wish I had taken a picture before I changed it to show the difference between "right and wrong".

Thanks so much for this thread...I know it's old but I finally saw it for the first time tonight.

[blackmist222777]

My car is totally fixed now... love this forum..!

[E92inSG]

I love this post. Special thanks to those who contributed the pics. Solved my headache.

Job made a lot easier on the hoist. I found reaching the rear sensor arm was much easier from the front of the rear wheel. Easy to understand how they could get this wrong. When the suspension is removed, the arm could easily fall into the wrong position.

[E92inSG]

Just to add on, when the rear sensor arm is hanging down (wrong) the auto leveling still works. It's just that the system thinks that the rear suspension is super jacked UP. and compensates by pointing the headlights to the highest position.

[OC3]

The collective body of knowledge/info on this forum is simply amazing.

[micha3l]

Awesome thread, I knew something was different about my lights at night after the suspension install!

Literally 5 min fix, didn't even need to jack up the car.

[SYZ]

good info. just ran into this problem, and low and behold, here is my answer.

[M3anRide]

Originally Posted by JAJ

Attachment 388805

In the wrong way, you position the sensor arm (at the top, plastic with cross ribs) hanging straight down, so the H-shaped arm that links it to the bracket at the bottom reaches sideways instead of up and down. In that "wrong" position, there's no stress on the sensor (it doesn't get broken) but it doesn't work either. Hence the system locks the headlights in one place and waits for someone to repair it.

When I undid the sensor arm and moved it up (to where you see it in the picture) the headlights started to move as I moved it. System function was fully restored, and there was no need to adjust the manual headlight adjusters.

So, if you're one of the guys who've had to do a manual headlight adjustment after a spring or suspension install, check the rods and arms on the rear headlight sensor. If they don't look like the picture, get it checked out by a qualified mechanic.

[By the way, if you look at the photos on an iPad, they're the wrong way up. On my PC and Mac browsers, Chrome, IE, Safari and Firefox, they work fine. On the iPad Safari browser, they revert to the original camera orientation, which was determined by getting the lens aimed at the sensors for the pictures. The front picture was taken upside down and the rear was taken sideways. If they look strange, switch browsers.]

Thank you because of this post I was able to find out why my headlights were riding high without needing to adjust my headlights. I simply opened the picture (maximized) on my iPad, locked the orientation, jacked up the back end and orientated the picture and the suspension. Very quickly I was able to see it and with the left rear wheel hanging down I was able to flip the sensor to the correct orientation. Thanks again!!!

[Rk-d]

Originally Posted by M3anRide

Thank you because of this post I was able to find out why my headlights were riding high without needing to adjust my headlights. I simply opened the picture (maximized) on my iPad, locked the orientation, jacked up the back end and orientated the picture and the suspension. Very quickly I was able to see it and with the left rear wheel hanging down I was able to flip the sensor to the correct orientation. Thanks again!!!

Ditto - was getting tired of being flashed. I was just about to manually adjust the lights til I found this thread. It was tricky getting the nut off - I tried doing it with the wheel on and wasted a lot of time. Ultimately, I jacked up the car, removed the wheel and had the thing adjusted in 10min. Great tip.

[Endless619]

Good info and should be a sticky...

[Ben Ingraham]

This thread is a life saver. However, if things are this easy on the car, it will considerably cut down on father son time in the garage. Awesome pictures.

[Wei718]

Wrong way!



Right way!

[Raz335]

Bumping an old thread just to say that this was very helpful. I recently had my Eibachs installed and been driving around with my headlights pointing way too high. After checking the rear sensor, sure enough it was re-installed incorrectly. If you can jack the rear of the car up high enough, you can do this job without taking the rear wheel off. It's easier to stick your hand in front of the rear wheel to get to the 10mm bolt. Simply undo this bolt from the camber brace, flip the sensor arm and swing arm assembly to the proper position (see picture in post above) and re-install bolt. Took me 10 mins. My headlights now cycle properly and I'm no longer blinding people and receiving honks.

[newa///M]

Just wanted to say thanks to the OP and all those who contributed . I had the same issue with my headlights aiming too high. It's back to normal now. The wealth of knowledge in this forum is incredible!

[FazerBoy]

Bumping an old thread but I had the same problem with my headlamp aim being too high after the installation of subframe bushings.

After reading this thread I realised that the problem must be the rear sensor so I removed my wheel and indeed it was.

Through not reading carefully enough about the need to remove a bolt to flip the sensor assembly I just pushed it at the junction between the two rods and it just flipped into the correct position without me removing any bolt. It did this quite easily without me forcing it too hard. My headlights are working now.

Now that I have properly read the thread I wonder whether I have found a short-cut method to re-installing the sensor to the correct position (ie without the need for tools at all) or whether this was a dumb thing to have done and risked breaking my sensor?!

[FormulaMMM]

Bump for an awesome and informative thread. Same issue for me post-Clubsport install.

Before



After



Issue resolved.

Bolt spun for me trying to remove the nut, so used a 3/8 wrench to hold it in place.

[Tortoise]

I had the same experience after installing my KW CS kit. I reassembled the rear assembly the wrong way and the lights were pointing too high. I had been flashed a few times and knew they were out of whack, but thought the dealer could adjust it during a routine service for oil, plugs and diff fluid. I was wrong. They knew they were high and told me they had to lower them a little (they were still too high). Now that I've reassembled the sensor arms the right way, I've got to figure out the correct height to undo the dealer's "fix".

Great post. I wish I had found it two weeks ago!

[blast1st]

This thread helps a lot thx guys

[dc779a]

I recently purchased my M3 and noticed the headlights were aimed quite high. I was about to adjust them when I figured I should check the forum. A quick search revealed this extremely helpful thread. Looks like with the previous owner installed the H&R springs they installed the rear arm incorrectly. With the images I diagnosed the problem and had it fixed in a matter of minutes. Thanks for making this thread OP!