Ever since I put new tires on my 2002 SL500 and had it aligned it drifts to the right on both freeways and surface streets. I have checked the alignment and was told by my indie MB mechanic that it is set perfectly on the alignment machine. I understand that this may be normal on freeways which are crowned (but even in the #1 lane which appears to be crowned to the left?).

a) Is there a trick to aligning the SL500?
b) Does it have to be set to track slightly to the left to cause it to track
straight on the road?
c) Is this an inherent problem with the SL500 that my mechanic is not
aware of?

It is very annoying so any help would be appreciated.

Thanks,
Mike

 

im no expert in these matters, but i believe the key lies in one point..NEW TIRES..
if the problem was not exhibited before the tire change, it seems logical to look there.
id suggest air pressure , assuming that you replaced them with the same or recommended
size...i have a 2003 sl 500 and it is quite sensitive to air pressure variation in ride and steer.
any comments on tire type , size and pressure.

 

Good point ab4jy. Almost everyone says their MB pulls right. If your mechanic was a little lazy and didn't set the rear toe this could be an issue also. Many times on alignments the rear toe can be in the green but the track angle can be wrong. causing a pull. I like to set the track angle positive a little. This will help fight the pull to the right. Did he give you a print out? If so you can see what the track angle is. If you have a tire pull. Rotate the front tires left to right and see if the pull changes. The car will pull to the bad tire.

 

Thank you both for writing. Interesting that others have the same issue. The tire pressure is 33# front and 36# rear as recommended. How much can I safely lower the pressure F & R to improve the ride quality?
I will take the car into my mechanic and have him check the track angle. Is this only set on the rear tires or both front and rear?

 

I have been busy with re-calculating tire-pressure since 2007, with use of the same formula and its addings, the European Car and Tire-manufacturers also use to determine the advice pressures for cars.
Learned myself Excell to make spreadsheets for it and translated a few from my native language to Englisch ( so Tyre instead of Tire, and sorry for miss-spellings and wrong terms).

http://cid-a526e0eee092e6dc.skydrive...0tyre-pressure
in this map the spreadsheet with excample.
If you fill that in right with all the asked data of the first apearing sheet, then you will get 6 advices, for normal use( if old advice pressures normal use advice is given) , Heavy use and vacation use. And those for up to 2 maximum speeds.
This advice must be seen as a minimum for the loads they are calculated for. but mostly the actual load is less then the load the advice is given for.
Then you can pick the use and maximum speed you use and see if you can savely go lower.
Mind that the American TRA used before 2005 a formula wich gives lower pressures so warmer tires,and are still busy changing it in the direction of the ETRTO formula. But you can calculate a TRA-typed tire with the European ETRTO formula because tires of the same sises and sort are phisically the same, and you will come to saver advices. When the advice is lower then the TRA advice, it is because ETRTO formula can savely go down to 22 psi and TRA had to stop at 26 psi, otherwise the tires get to flat and so to warm wich can give damage an tire-blew-out.

Even the alignment sometimes can influence the needed pressure. When the camber-angle( tires placed like this /-\ on the axle) is above 2 the pressure must be higher, but you can fill it in in the spreadsheet. You probably have a paper with the alignment figures because you had it done.

If there are questions,ask them here or mail me at hotmail.com with the same username as here, and give it a title that cant be confused with spam.

 

If a car drifts to one side it may be the camber setting.

 

Air and Tires could be an issue, the toe set could be straight and may need to be set in a little.