PASl50005

I've got a 2005 SL500 that drifts to the right. So much that, starting in the left hand lane of a highway, it will drift up and over the crown and continue to the right. Dealer has aligned twice with no success.

Any thoguhts would be appreciated.

djamer

Sorry to hear about your alignment issues, but judging from the complaints fellow benz owners have written regarding SL models, there is a pattern of complaints which relate directly to the quality/workmanship of this car. Not to bash benz cause i own one and i have experiened my own problems w/ my car; all I am saying is benz should do a much better job in Quality Assurance before selling their products..just my 2 cents..

here's the link which may be helpful to you.
http://www.mercedes-benz-usa.com/sl_class.php

jasab

Sorry to hear of your problem. The car should be spot when leaving the factory.
What reason did the dealer give?
It sounds severe. Have you thought about rejecting the car on the grounds of being unstable?
Although you shouldn't need grounds when spending so much money!
Give the dealer hell.

Good luck!

WIldcat465

I took my '05 600 (only driven 400 miles) to the dealer yesterday for the same problem. I'll see the results today.

My '03 Launch Edition tracks perfectly.

dmccorki

check with this site and others. there has been lots of discussion on the problem. my 2004 sl500 was at the shop 4-5 times. they realigned, changed tires, etc. they finally fixed by changing the bushings in the front end. mercedes knows about the problems and, i am told, has a technical bulletin out on the subject.

LovinMercedes

I am not saying this is the case with you but I have had this "so called" problem in the past. You have to remember, roads like highways have a natural slant to them to drain water so it is very difficult to test your alignment on highways or some roads. Some highways or roads have greater slants than others. Usually the car can hold the slant if it is not too great but I have personally found myself letting the steering wheel alone and watching the car drift. A drift could be fine, a sharp pulling would not be.

I have then taken my car to a known flat area and found that it goes perfectly straight when the steering wheel is left alone.

Just a tip in case you may be having the same issue. You'd be surprised if you stand back and look at a road how slanted they can be. Most are especially in areas where there tends to be a lot of rain.

Good luck.

Chris 45971

I agree Lovin. My car drifts (slightly) to the right all the time. At first I was concerned. However, after further observation, I have notice that it is because some roads where I drive are slightly slanted from the center to the right side. To prove my observation, I drove on the other side of the road and on perfectly flat (seemingly) highways and parking lots. When I am on the other side of the slanting road, the car will pull to the left with the similar slant that goes to the left and on flat roads and parking lots, strait ahead. I have notice that wind can put the car all over the road as well.

My old car never never did this on the same roads (or if it did, it was to a much lesser extent that I didn't notice). I think the extra weight and the larger sport tires on my SL grab/feel the road better which results in the "pulling" to every contour of the road.

After reading the Pasi50005's initial post, I don't think his car applies to the above. His case sounds like there is actually a problem, but for the many that I see at this forum who mention the "pulling problem"; I think this could be the reason.

Just a thought.

super_SL500

I have a problem where the tires are wearing on the inside. I am on my third set of tires.

LovinMercedes

If your tires are wearing on the inside that is absolutely an alignment issue.

PASl50005

I sent it back in yesterday and the dealer believes that this time they have found the problem. They are replacing a tire.

Will let you know if this fixes the issue.

speed

MY new 04 SL600 had this problem of right drift right from the start. They had to change the front right tire twice and that solved the problem. Do not let them mess with your suspension until they have checked the front tires.

PASl50005

And it fixed the issue!

cyberay

I have had 2 SL500's previous to the '05 I have now; an '03 and an '04. All three have responded to tire pressure in exactly the same way. At the recommended settings of 26 front 29 rear a drift to the right was noticeable regardless of road crown. When I adjust pressures to approximately 34 front and 30 rear, steering becomes neutral. Apparently the slight change in caster resulting from the change in pressure is enough to affect steering feel. Give it a try, I doubt it has any effect on tire life. The only handling difference is a much better on-center feel to the steering.

LovinMercedes

I am perfectly centered at 27 and 30.

tiggerfink

Is the center of your front tires wearing faster than the sides?

vraa

So you replaced a single tire?
Heh, that's cool!

cyberay

Tiggerfink: My tire wear has been evenly distributed on all the cars I've mentioned. I believe that MB specifies higher pressures in the rear to reduce the possiblility of oversteer which is more dangerous than understeer. I've found the 34 front 30 rear bias improves handling slightly, allows the car to track straight and true, and does not adversely affect tire wear.

LovinMercedes

I have been told that over inflating your tires does have an effect on your tire life as well as decreased ride comfort.

carlosfernandez

How did you check your tire pressure, with the Tire pressure monitor of the car or using other instrument to messure it?

cyberay

Lovin: Comfort is subjective. Some like a firm ride, others cushy. You are right that overinflation will decrease tire life as well as affect the ride. However, tire pressures in the 30 to 34psi range are far from overinflation, especially when the weight of the SL is considered. I would consider 40psi to be overinflated and at that pressure you would probably start to notice some dartiness on the highway. This is mostly caused by a decrease in the footprint of the tire on the pavement caused by the high pressure pushing out the center of the tire. Last week I took delivery of a new SUV and the dealership either failed to check the tires or thought they were being helpful by filling them to 42psi. On the way home on the interstate it felt like strong crosswinds were keeping the vehicle from tracking straight, except there were no crosswinds. The first thing I did when I reached home was check the pressures and adjust them down. The next time I used it on the interstate I noticed it tracked well and the dartiness was gone.
I don't agree with the low pressures that most manufacturers specify as I know that product liability is as much an issue for them as is handling and tire life. I have owned many different types and brands of vehicles over the years and have pretty much used the same pressures I'm using now. I've always gotten acceptable life from the tires for the conditions they were subjected to, and at the same time been satisfied with the handling they provided. Years ago during the age of the land yacht manufacturers would specify low pressures to enhance comfort at the expense of handling even though this shortened tire life and made for some pretty mushy turning. Now due to suspension and tire design improvements this is not necessary for comfort. I believe it is done to induce understeer, the tendency for the front of the vehicle to slide, when pushed to it's limit of adhesion. While this is not a particularly good thing, it is better than the alternative of oversteer where the backend breaks loose first and comes around and gets in front of you, which is much harder to control. There is no doubt that tire pressure is a very critical component of driveability and safety, but there is room for tweaking that which is specified by the manufacturer so that some amount of personal preference can be addressed. BTW, pressure affects only the caster component of wheel alignment and caster has no effect on wear. It's the toe adjustment and the camber angle that cause the outsides or insides to wear prematurely. Underinflation will also cause the shoulders of the tires to wear quickly leaving the centers looking unused. That's because when turning, the shoulders tend to roll under and scrub, and when going straight the centers are receiving less of the load - just the opposite of overinflation.

Carlos: I have a very good and very old analog type guage, the type that used to be used in service stations when they were "service" stations. It is still accurate to about 1 psi.

Hope I haven't bored anyone with this long-windedness but it's Sunday here in paradise (Hobe Sound, Florida) and I haven't yet decided how to spend the day.

carlosfernandez

Don't worry, Here in Puerto Rico my wife is sleeping and I also dont know where she want to go. BTW if the tire pressure monitor of the car is an accurate as the manual ones? just to know because I use the car presure but not sure is so exact?

LovinMercedes

I understand.

Enjoy your Sunday. I know what you mean having spent 10 years of my life in sunny Florida.

cyberay

Carlos, I don't know just how accurate the tp monitors are, but I do know that the manual ones come in all flavors. Some are accurate and some aren't, and the determining factor is not necessarily the price. So I suppose, the answer to your question is that the monitors on the car are likely as good as what you are going to get from the auto parts store as long as you take your reading with the tires cold. Also in a climate like that of P.R., strong sun can run the pressures up a couple of psi on the tires that are exposed to it when parked. So take that into consideration when checking your display and don't be too quick to bleed air from tires on one side of the car.

carlosfernandez

Thanls for the info.