How to raise headlight aim???

[skyegtb]

OK, I actually know how to manually raise my headlight aim and have done it numerous times over the years, using Vagcom in block 55 to set the 'level' then turn the cogs on the headlight to raise / lower the beam and then 'confirm'. I do however have a long running problem with my lights, and that is that even with the manual aim at the maximum for both lights it is still lower than I would like, and does not give enough distance range on dipped beam. Therefore, the question really is 'How can I raise the headlight aim above the maximum that the adjusters will allow'!

To give more background, I have just fitted 2 replacement lights to the car. I refurbished these over the winter and replaced the damaged / missing adjuster cogs and re-lacquered the lenses to make them like new again. Both the original lights on the car had the typical missing adjuster cogs and one of them was broken inside and will require gluing to repair.

Anyway, the old lights were adjusted at their max height and just about gave me the beam that I desired, perhaps just slightly low, but just about acceptable. The new lights I just fitted are just about the same, but again totally maxed out on the height adjuster. I have checked everything over on the car related to the automatic height adjustment and everything is in spec and no fault codes are found. The lights always do the 'self levelling' test when turned on and generally everything is normal. For info, I disconnected the self levelling arms on the front and rear suspension and tested the voltage with Vagcom - they both read from a minimum of 0.5V to a max of 4.5V. When the car is sitting on level ground the front voltage is 2.03V and the rear is 1.83V - all within limits. I also tested the headlights moved when these were manually adjusted by raising the car off the ground on my lift, and manually adjusting the arms. I confirmed that the aim would lower and raise depending on the movement of the front / rear arms.

As the bumper is off the car I have played about with the mounting screws to tilt the headlight upwards as much as possible before tightening the screws, but this does not achieve a particularly big improvement. So, is there any way to get these lights to aim higher and possibly allow me to not have them at the max height adjustment all time?

For info, my other car is a 2001 A6 C5 allroad with very similar headlights to the RS6. On that car the manual aim adjustment is approx in the middle and the adjusting screw allows a huge range of adjustment if required. Why are the RS6 lights so different? Is it something as simple as the actual height adjustment screw on the RS6 is shorter than the A6 screw? Can the A6 screw be fitted to the RS6 headlight? Has anyone done this before?

Looking forward to any opinions / advice. Currently I am thinking of stripping down my old RS6 lights and an old allroad light to compare the innards in detail. I will report back with my findings.

[Shoppinit]

Your adaptation set to the right model?

[skyegtb]

Your adaptation set to the right model?

I'm not with the car just now to check, but does the scan below show the value / coding?

Address 55: Headlight Range Labels: 4Z7-907-357.lbl
Part No: 4Z7 907 357
Component: dynamische LWR D09
Coding: 00050
Shop #: WSC 00000
VCID: 040C51BB141B18A965-4B18

No fault code found.

[Shoppinit]

Your coding is the same as mine so it's not that.

Have you carried out the basic settings on level ground before adjusting? It's not an intuitive procedure.

[skyegtb]

Yep, I set it on the ground first and it took the level first time without error. I have a mark on my garage door with the previous 'good' levels for each headlights and it came up very close to that, BUT the issue is that the units are maxxes out on the manual adjusters to get there....

[Shoppinit]

Sure. Just checking that you were telling the car what the zero position was and it wasn't using some previous setting.

For a laugh, you could try jacking up the rear a bit and setting the level. If only to see if your basic settings are being taken.

IIRC the linear stepper motor pushes and pulls the bottom of the lens which is hinged at the top. There might be scope to adjust the position of the stepper so that its zero point is pushing the bottom of the lens out a bit. I can't remember exactly how it's put together. I'd have to look at one of mine.

[skyegtb]

Good idea about jacking up the rear, I was also thinking about trying that as an experiment as well! One other thing I am going to do is physically lower the rear of the car by 10mm, run the basic setting again and see if the lower rear gives just enough extra height in the beam. Since I bought my car in 2008 the rear has been higher than I would like, but I never got round to levelling it to the same as the front, as it never bothered me *that* much. The car has the KWV3 coilovers on it and the suggested height they recommend gives the car a 'muscle car' stance - raised at the rear, slammed at the front! I have seen this with many other KW cars over the years. Anyway, I have a strong feeling that my adjustment will very likely make a noticeable difference to the beam aim, but I also still believe that I will be maxxed out on the adjusters.
As I have a set of RS6 lights and a set of allroad lights sitting on my bench I am going to rip in to both and see what the differences with the height adjusters are. I just cannot understand why the RS6 ones seem to have the same range of adjustment as the A6 ones, yet the RS6 top out too early.
Here is a pic of my current ‘stance’. You can see the rear is a lot higher than the front. How does your car sit? Is it level front to rear or is the rear higher or lower than the front?

[Shoppinit]

Yeah, mine is level. I would definitely lower the rear on yours. That will give you an extra degree right there. Looks like you're 2 cm higher at the back over, what, 4m? 40m out from your headlights that's 20cm beam height.

Concerning the difference with the A6, it could be that the adjustment range is limited because of the automatic levelling - different mechanicals. I'm not sure how much value there is in comparing them.

[skyegtb]

Yep, going to lower it ASAP, then do some tests, perhaps that is the only issue here and it would be ridiculous that I have waited 15 years to make this adjustment!!!!
For info, the A6 lights have the same self-levelling motor as the RS6 due to the fact the allroad (which has Xenon lights) uses the same level sensors as the RS6, with the only difference being that they are on all 4 corners, not just the passenger side. It will be interesting to compare on the bench at least.
I'll report back!

[skyegtb]

Yep, going to lower it ASAP, then do some tests, perhaps that is the only issue here and it would be ridiculous that I have waited 15 years to make this adjustment!!!!
For info, the A6 lights have the same self-levelling motor as the RS6 due to the fact the allroad (which has Xenon lights) uses the same level sensors as the RS6, with the only difference being that they are on all 4 corners, not just the passenger side. It will be interesting to compare on the bench at least.
I'll report back!

OK, all sorted now  Firstly, lowering the rear of the car by 12mm made it very close to level with the front. The effect of this on the lights is that it did raise the aim slightly but not massively. Probably this did put the lights at very close to the perfect level, but stil a tad too low, and this was still with the adjusters set at the max. What I did next was to fully strip down both an RS6 light and an allroad light. Basically, they are almost exactly the same inside and sadly there was nothing to be learned from the allroad light as the function was identical. What I did learn however is that the reason the RS6 lights max out in the position they do, is that the height adjustment screw in the plastic lens holder (the screw that is turned by the adjuster on the outside of the lamp) bottoms out in the adjuster at the max point. I removed the screw and the black plastic adjuster and modified both by cutting 5mm off each, then reinstalling in the light. On re-assembly this gives the necessary extra height adjustment required without affecting the strength of the mechanism or anything else. With the lights back on the car I finally have the beam correctly set with way more vertical adjustment left in the mechanism than I would need, therefore the mechanism is no longer ‘maxed out’. I will take some pictures of what I did to explain it better, but it was very simple other than having to re-glue the adjuster cog back on to the adjustment screw.

Just had a thought - I have the 2 old lamps to restore in the future, so I will make this mod to both of them when doing the renovation. I will take loads of pics and do a write-up on it in case it helps someone in the future.