08 Rx Low Beams

[GDixon]

I don't drive much at night but recently drove a very dark, undulating, and curvy road in the rain at freeway speed. It seems that the sharp cut-off at the top of the headlight's low beam limits the view of the road severely. Upcoming turns cannot be seen and when going down into a dip the road ahead is not illuminated at all. Oncoming drivers must love it but it is disconcerting on an unfamiliar road.

Has anyone replaced the OEM lights with something that has a bit more forgiving top edge? If so, what was used? If you have a brand name and/or part number it would be helpful.

The high beams are fine and seem to light up the road for miles.

Thanks.

[asianrage]

Does your car come with HID option?

[GDixon]

Does your car come with HID option?

Yes, it does. I can't say that it makes much difference or is noticeable.

[wwest]

I don't drive much at night but recently drove a very dark, undulating, and curvy road in the rain at freeway speed. It seems that the sharp cut-off at the top of the headlight's low beam limits the view of the road severely. Upcoming turns cannot be seen and when going down into a dip the road ahead is not illuminated at all. Oncoming drivers must love it but it is disconcerting on an unfamiliar road.

Has anyone replaced the OEM lights with something that has a bit more forgiving top edge? If so, what was used? If you have a brand name and/or part number it would be helpful.

The high beams are fine and seem to light up the road for miles.

Thanks.

"drove a very dark, undulating, curvy road in the rain at freeway speed."

AT FREEWAY SPEED

You have a death wish, maybe..???

Otherwise, say an emergency situation, turn on the hazards and go ahead and use the high beams. Oncoming drivers will be very forgiving in your situation.

[LexKid630]

There's nothing you can do as far as bulb replacement, for the problem is the unit not the bulb. It's not actually a "problem" it's just the way lexus made them. You know how, when you start the car, the headlights move up and down (along with left and right) ? This is the auto-leveling system. Under the car, on the right rear control arm, there's a little "lever-like" piece of metal that's attached to a sensor. If you have a lot of weight in the rear of the car etc, the control arm pushes down (or something), and ends up moving the lever. This tells the car, to angle the headlights down (for the front of the car would be angled up at this point) so oncoming drivers don't get blinded. If you remove the bolts holding this lever-sensor assy. together, and move the lever with your hands you can basically control the angle of the headlights yourself. Find the position you like, and wrap it up with some duct tape etc. I did it on my rx300; i'm assuming it will be the same for the rx350.

I actually did some serious wiring and brought the sensor in the cabin area so i can change the angle of the headlight beam from the drivers seat! The only thing is, you can only change the angle while at a very low speed. If i move the switch at a high speed, it won't actually work until i slow down. I think every lexus should have a manual switch in the cabin!

[GDixon]

Thanks for the hint - very informative.

[GDixon]

Thanks again for the try to help out. I was just over on the IS forum and someone was having the same headlight aiming issue. Apparently there is a very obvious fixture near the driver's side rear axle on an IS. One would think that Lexus would use the same fixture on the RX. All of the pictures of the thing were gone however and the picture poster didn't have them anymore.

Crawling under the 2008 RX350 with a flashlight did not reveal anything that looked adjustable except for the large bolt adjustments for the swing arms and anti-sway bar. If LexKid630, or anyone else for that matter, can provide a picture of the device it would be very much appreciated.

All around both sides of the rear axle were inspected but without a solid visual clue about what to look for it was fruitless. The device must work on the principle that LexKid630 mentioned. A fixture attached to the unibody on one side and the axle on the other side measures the distance, probably by a rheostat set-up, and the electrical signal is interpreted by the computer and the headlights adjusted.

It will probably be simple once it is tracked down. In the meantime, my wife is reluctant to drive the car at night and I find it disconcerting.

[LexKid630]

I can't take pictures of the device on the RR control arm since i had to remove it, to take it into the cabin to make the manual switch.

Find the control arms and find that little "arm" that connects from the right-rear arm to the body of the car. I have attached a little diagram i did quickly on paint to show what i'm talking about.

[GDixon]

Great diagram! I know it takes a lot of time and effort to do such things and it is very much appreciated. I was looking for something smaller than the diagram shows so I'll try again.

By the looks of the photo that you drew on, the lever is on the passenger's side rear ("right-rear arm"). The IS people have theirs on the driver's side. I'll check it out and take a picture if I can find it. Maybe someone else will be helped out with a posted picture. Your drawing should be enough for a good mechanic but a picture of the actual device may work better for the more challenged among us.

Figuring out how to mount an adjuster in the cockpit is no small feat - very impressive. :D

[wwest]

Great diagram! I know it takes a lot of time and effort to do such things and it is very much appreciated. I was looking for something smaller than the diagram shows so I'll try again.

By the looks of the photo that you drew on, the lever is on the passenger's side rear ("right-rear arm"). The IS people have theirs on the driver's side. I'll check it out and take a picture if I can find it. Maybe someone else will be helped out with a posted picture. Your drawing should be enough for a good mechanic but a picture of the actual device may work better for the more challenged among us.

Figuring out how to mount an adjuster in the cockpit is no small feat - very impressive. :D

I think the self-adusting/leveling is disabled above ~15-20 MPH.

When I first converted my '01 to bi-xenon (DIY) I tried modifying the sensor signal from the rear axle but found it wouldn't work above ~20MPH.

[GDixon]

Maybe the speed limiting issue is because the car would tend to bounce more over a bump at speed - or just travel in more of a wave pattern that would cause the mechanism to constantly adjust. The suspension-dependent device would also be compressed/extended more often at higher speeds. Perhaps the thing is designed that way to prevent premature wear out fatigue. Just a guess.

Anyway, the RX will be put up on ramps to see if I can find that bugger and adjust it. It is bit of a tight fit while on the ground and also a camera wouldn't fit under there very well. Just need to find the time to do it.

[LexKid630]

At lower speeds, the switch is very responsive and the light angle can be adjusted as soon as i move the switch (i just need to move it very slowly).

At speeds above ~20MPH the switch must be left in one spot for several seconds before the headlights move.

[GDixon]

OK, I finally got off of my rear and under the car's rear.

The headlight adjustment is a bit different for the 08 RX than what has been described in this forum and the IS forum.

Attached is a picture of the adjustment device. It is on the passanger's side rear swing arm. Shortening the adjustment arm pulls the lever down and the result is raising the headlights' aim. Since I rarely drive at night the aiming was done on a garage wall. The adjustment doesn't seem very sensitive and at five feet the top edge of the light only came up about 1/2 inch when the adjustment arm was shortened about an inch. If my math is correct it will come up about 10 inches at 100 feet and 30 inches at 100 yards. We will see what happens on the next night outing.

Oh, the adjustment nuts are 10mm. You will need two such wrenches. The pivot attachments have an 11mm square base. The nuts are very hard to move if the threads are dirty so a shot of WD-40 might help. It is a bit tight under there to work with the required two hands/two wrenches so jacking up the car or putting it on ramps helps access.

[tbear2]

Here is the procedure. Do not adjust the arm under the car

How do I upload the diagram?

for HID headlight

(1) Adjust the aim vertically:

Adjust the aim of each headlight to the

specified range by turning aiming screw A with

a screwdriver.

NOTICE:

• The high-beam light aim moves in the

vertical direction and the low-beam light

aim moves in the diagonal direction

when aiming screw A is turned.

Remember the turning direction and the

number of turns of aiming screw A to

correct the horizontal position of the lowbeam

in the next step.

The final turn of the aiming screw should

be made in the clockwise direction. If the

screw is tightened excessively, loosen it

and then retighten it, so that the final turn

of the screw is in the clockwise direction.

(2) Turn aiming screw B the same number of turns

and in the same direction as aiming screw A.

NOTICE:

The final turn of the aiming screw should be

made in the clockwise direction. If the

screw is tightened excessively, loosen it

and then retighten it, so that the final turn of

the screw is in the clockwise direction.

HINT:

• Since the low-beam light and the high- beam

light on each side have separate reflectors,

it is necessary to check and adjust the aim

separately for both.

• If it is not possible to correctly adjust

headlight aim, check bulb, headlight unit,

and headlight unit reflector installation.

Do not cover the other headlight more than 3 mins or the plastic lens may start to melt!

[GDixon]

To upload a diagram or picture look directly under the box used for messaging/replying with "Attachments" in the upper left corner. On the right find the box with "Browse", click on it, and look on your computer to find the file. If it is in "My Documents" on a Windows computer it is easier to find. Click on the file to get it to appear in the attachments box. Then click "Upload" and wait for awhile depending on your connection speed. If the upload fails then you may have to convert the file to *.pdf or *.jpg with a scanner.

Then find the uploaded attachment in the "Manage Current Attachments" box and click on the far left icon to add it to your message. Have the cursor located where you want the file to appear. Click on "Preview Post" a little further down the post page, below the icons, to see if it worked. Good luck.

BTW, I'm not sure why tbear2 recommendations not adjusting the adjuster by the rear wheel. I finally got to drive at night and the adjustment was perfect. The road was illuminated at least twice as far and my wife will now drive the RX at night. Nobody flashed his/her headlights to indicate being blinded.

[tbear2]

GDixon,

The method I posted for adjusting the headlights is from the service manual. I've included the same text as my last post and added 2 diagrams showing the correct adjustment screws. Remember the 3 min maximum rule for covering a HID light from my previous post. You don't want you plastic headlight lens to melt.

If you adjust the lights under the car as you suggest, I don't know the advantages or disadvantages. It might change the geometry, making the headlight adjustment more or less sensitive to a heavy load in the rear of the car. I just brought home 4 snow tires on wheels last week and noticed that with that heavy weight in the rear the lights became adjusted too low! I'm going back to the dealer to see if the self leveling can be corrected. I assume they will do that by adjusting the device you described and then bringing the lights back to spec with the screws behind the headlights.

Thank you for explaining how to add an attachment. RX350_He...djusment.

RX350_Headlight_Adjusment.PDF

[GDixon]

You read directions well. The upload worked.

The tires' weight won't have anything to do with the headlight adjustment since they do not cause the body to sag - they are unsprung. The device works by measuring the distance between the body and the swing arm. If the snow tires in back are a different diameter than the ones in front then there may be an issue.

Maybe someone more knowledgeable on the headlight alignment, like LexKid630, might have an answer to the misalignment/tires issue. He might have installed the adjuster within reach just for the reason that you are experiencing.

[tbear2]

The 4 tires and wheels were in the rear compartment, not on the car. I was taking them home to swap them for the summer tires/wheels. They are fairly heavy and did lower the rear of the RX noticeably. By the way I am disappointed in the snow traction and skid control of the RX compared to my previous vehicle an Audi A6. With similar tires the Audi was significantly more capable than the RX. I didn't expect good handling from the RX, but I did think it would perform better in the snow. If I had not had the prior experience of the A6 I might have thought that this is as good as AWD gets. The viscous clutch and electronic controls are not as well engineered as I expected. Oh well, at least it is much more reliable.

[LexKid630]

Just take everything apart and off of the control arm and bottom of the car, and manually move the switch with the car on with the headlight on. When you find the angle you want, ducktape the heck out of it wrapping the tape around the switch holding the little arm in the position that gives you the best angle. Then somehow attach it to the bottom of the car so it doesn't fly around.

That little arm doesn't need to be attached to the control arm and the car. Its only function is determining the weight in the back of the car. It's like a thermometer, it doesn't affect the temp, only records it.

[LexKid630]

also, i wouldn't play around with the screws on the headlight unit to adjust the height; it's gotta be a pain in the @SS to get each side to be equal height when adjusting them sep.

[GDixon]

The 4 tires and wheels were in the rear compartment, not on the car. I was taking them home to swap them for the summer tires/wheels. They are fairly heavy and did lower the rear of the RX noticeably. By the way I am disappointed in the snow traction and skid control of the RX compared to my previous vehicle an Audi A6. With similar tires the Audi was significantly more capable than the RX. I didn't expect good handling from the RX, but I did think it would perform better in the snow. If I had not had the prior experience of the A6 I might have thought that this is as good as AWD gets. The viscous clutch and electronic controls are not as well engineered as I expected. Oh well, at least it is much more reliable.

The Audi A6 is famous for its ability in snow and ice. Anything else would seem to be a step down.

The snow tires carried in the luggage area would certainly cause the headlights to be lowered. It sounds like they may have been lowered too much by the signal from the adjustment lever in the rear. I'm guessing that you would rarely carry such a load so any modifications may not be necessary otherwise they will be consistently too high. Adjusting them for a single hauling session and then adjusting them back doesn't seem to make sense unless you have a setup like LexKid630 and can do it from the driver's seat.

[GDixon]

That little arm doesn't need to be attached to the control arm and the car. Its only function is determining the weight in the back of the car. It's like a thermometer, it doesn't affect the temp, only records it.

My thought is that the headlight controller acts more like a home HVAC thermostat. A thermostat measures the temperature and then acts in conjunction with the furnace or A/C by sending an electrical message.

With the headlights, the gizmo in the rear sends a message to the adjusting motors to raise or lower the angle of the headlight beam. It probably is just a rheostat and the amount of electrical resistance is the determining factor for the message to the motors.

[LexKid630]

Oh, i just used said that to explain that it's ok to remove the little arms etc from the control arm and under the car. Meaning, the car will function perfectly if you remove it.

That's what i did on my rx300 and rx350. I just took everthing apart and brought the switch into the cabin so i can move the headlights manually. I love it because i like to adjust the height based on my surroundings. i just move the little wheel and BAM they go up or down to my liking. I'm basically doing the little arms' job!

[triplecore]

There's nothing you can do as far as bulb replacement, for the problem is the unit not the bulb. It's not actually a "problem" it's just the way lexus made them. You know how, when you start the car, the headlights move up and down (along with left and right) ? This is the auto-leveling system. Under the car, on the right rear control arm, there's a little "lever-like" piece of metal that's attached to a sensor. If you have a lot of weight in the rear of the car etc, the control arm pushes down (or something), and ends up moving the lever. This tells the car, to angle the headlights down (for the front of the car would be angled up at this point) so oncoming drivers don't get blinded. If you remove the bolts holding this lever-sensor assy. together, and move the lever with your hands you can basically control the angle of the headlights yourself. Find the position you like, and wrap it up with some duct tape etc. I did it on my rx300; i'm assuming it will be the same for the rx350.

I actually did some serious wiring and brought the sensor in the cabin area so i can change the angle of the headlight beam from the drivers seat! The only thing is, you can only change the angle while at a very low speed. If i move the switch at a high speed, it won't actually work until i slow down. I think every lexus should have a manual switch in the cabin!

Can you post a picture and actual instructions on how to do it? I tried twisting the lug not, but the hole stock twists and pliers can't fit in that tiny space. How did you do it?

Do I need a lift? I don't have one.

[GDixon]

I wouldn't recommend doing what LexKid did unless you are an accomplished mechanic.

There is a picture of the adjusting lever in the last post of page 1 of this thread. Loosen the nuts on each end of the center shaft. Then turn the center shaft with the center welded nut to make the thread area shorter (one thread is left handed). Tighten up the two end nuts and you are done.

My center shaft was adjusted about an inch shorter to make the correct headlight alignment. Be sure to check the alignment pre and post adjustment on a wall with tape at the top of the line of light. If drivers flash their lights at you at night then there is a problem and the shaft should be made longer.

The nuts are metric. The end nuts are 11 mm and the middle one is 10 mm if I remember correctly. Adjustable small wrenches would work also. A vice-grip could be used on the center nut if it is hard to turn or won't hold still while you loosen the two end nuts. Soaking the nuts and threads with WD-40 or some other penetrating lubricant first will help.

I didn't find the work space "tiny" at all so I hope we are talking about the same thing. Asking if a lift is needed but stating that you already tried to adjust the lever makes me suspicious that some communication is lacking.

No lift is needed depending on your size. Driving the passenger side rear wheel up on a 2x6 piece of wood will give a bit more room. Driving it up onto a curb will give lots of room for the adjustment.

A floor jack or even the Lexus jack is nice because the wheel droops down and the adjusting lever is somewhat more accessible. Be sure to use jack stands if you use this method.