centering the steering wheel - PeachParts Mercedes-Benz Forum

JHZR2 · #1 05-07-2003, 12:57 PM

Hi,

For a long time I have noticed something kind of odd, which now I want to get rid of. The steering wheel has to be turned slightly to the left side for the car to go straight. When I have the wheel set up to be at center, the car will drift to the right such that it can easily change a lane at freeway speeds. Oddly, the way that the Mercedes star is pointed in the wheel center, is such that when it is pointing straight up and down, the car will track perfectly straight.
I have had the car alligned twice, the last time being yeserday. It needed new control arms and a left tie rod, which I put on before this last alignment, with hopes that that was the problem. Also the steering wheel slop, which used to be over an inch of play is completely gone. The car now rides great, but the steering wheel is still off.

I would assume that the wheel is attached on some sort of a splined shaft, and so if I was to disconnect the wheel, and then move it one spline to the right, it should straighten out. Is thispossible? How would i do it? If that gets fixed, then my mercedes star on the wheel will be crooked with respect to the road -- how do I fix that?

Any help on this would be really great.
Thanks

JMH

md21722 · #2 05-07-2003, 01:18 PM

The proper way to align the car and center the steering wheel is to LOCK the steering box with the centering pin (That only locks it in center position). Once that is done, if the steering whele has been previously moved a few splines one way or another (INCORRECT procedure) then it should be moved back to proper.

BIGRED · #3 05-07-2003, 01:40 PM

It would seem that the alignment shop should have taken care of it. It could be that the steering parts are not adjusted properly. This assumes that letting go of the sterring wheel you drive straight. If it pulls to one side, than not only are the steering parts not adjusted properly, but the alignment is off as well.

leathermang · #4 05-07-2003, 01:40 PM

For sure Brian is correct with regards to not using the splines to get the wheel centered... however, isn't this supposed to be done at the tie rods when an alignment is done?
If you turn one adjuster ( the rod between the inner and outer tie rod ) ( after loosening the lock bolts ) one direction and the other the other direction... that changes the alignment at the steering wheel.... I think...

Also, you need to check the drift on a flat surface like a parking lot.. the crown in a road will cause it to go left if set up exactly neutral on the car...

md21722 · #5 05-07-2003, 04:48 PM

Old time alignment guys will tell you that toe-in is a TOTAL measurement. Think about the way Larry does toe-in. With regards to this, you can have perfect TOTAL toe-in with the tires turned 30 degrees, but the car won't go down the road straight. With the steering box locked at center, the tie rods are adjusted accordingly to give correct toe-in (& total toe-in) AND have a centered steering wheel.

HTH,

leathermang · #6 05-07-2003, 05:21 PM

This concept of " locking the steering box'... I am not sure all cars have that option. Not all steering wheels are adjustable with regards to the splines... I have seen them with a spline missing, which made it only one installation position.. the splines only being for stregth of connection. So I think some will have to rely on turning the adjusters and looking at the steering wheel to get all in accordance. I don't know how Larry does toe-in.... but I do not believe the concept of being able to set them at , for instance, your 30 degree turn example. They do not remain in their straight ahead relationship or they would really wear out tires....

md21722 · #7 05-07-2003, 07:18 PM

I'm not sure I understand all of your response. It may be true that some MB's have steering wheels that can't be moved or boxes that can't be adjusted. & yes, I agree that changing the adjusters on the tie-rods adjusts the steering wheel position. This is why the steering wheel should start out straight.

I mentioned my example because of his mentioned the car going crooked. Toe-in could be measured correctly with the wheels NOT parallel to the frame (with some equipment). Yes, the car will go crooked, and yes tires will wear badly - probably very badly! This is especially obvious for rear toe-in and introduces the "thrust angle". The toe-in can be fine, but if the rear tires are not parallel to the front tires, the car may go down the road crooked. Yes, tire wear will be bad and yes the car will go crooked.

I have had a lot of alignments and seen a lot of crazy things done to alignments. Some of the best use age-old Hunter Lite-A-Line's, especially shops that do custom vehicles - low riders, jacked up trucks, etc. Alignment is all about geometry, not computers. Light beams and a skilled tech will work MUCH better than a $100,000 Hunter and someone who doesn't know or core.

HTH,

leathermang · #8 05-07-2003, 08:54 PM

I do not believe the statement "could be measured correctly with the wheels NOT parallel to the frame " reflects proper procedure on the part of the person doing the alignment... since the car must be rolled forward (or backward) and it rechecked at the new postion to take out any tire set, etc...
I do not think that toe in can be set correctly at anything other than straight ahead.. and the people I watched do this in the old days simply pulled a string tight from around the rear wheel to the front and measured to see if they were parallel....
In other words, when doing the toe in the steering wheel, the rear wheels and the distance between the front tires all need to be kept as criteria... or something will be amiss....

jerryb · #9 05-07-2003, 09:10 PM

Find another alignment shop that knows how to do a M.B.
There is a plug on the bottom of the steering sector that gets pulled, then as the wheel is turned you can feel a dimple with a small phillips where it is centered, if they have the equipment and know how to do a M.B. they will have a tool that screws in to hold it centered. They also need a spreader bar to set tow. This is spelled out in the manuel, also their machine should tell them they need special tools, also ride height needs to be checked at the rear or caster could be off. Take it to the dealer.

md21722 · #10 05-07-2003, 11:24 PM

leathermang,

I am trying to show the difference between taking a toe-in value and taking a toe-in value that makes the car go down the road staight, with acceptable tire wear. Of course if a tech does it right, then everything will be Okay. But, that assumes the tech does it right or got lucky. My point is that the numbers can come back good but with the tech doing it wrong and the car driving incorrectly or tires wearing incorectly. Could be miscalibrated equipment or the tech no following correct procedures.

In my experience, I agree with jerryb, take it to the dealer.

leathermang · #11 05-07-2003, 11:46 PM

This was the statement which I do not think is correct ...

"you can have perfect TOTAL toe-in with the tires turned 30 degrees"

Where did that concept come from ?

I think that when the tires are turned there is no way this can be true...... the geometry changes....by definition.. no measuring of them in a turned position would be legit.... because the distance between them changes according to the number of degrees the tires are turned.. and you can't roll it straight in order to get the tire set out of it....

md21722 · #12 05-08-2003, 12:00 AM

Please re-read my previous message. If the tech does not do it right, he can still get the "right" numbers (even though the car doesn't drive well and/or the tires won't wear well). Its all up to the tech to follow correct procedure. Even with computers the numbers can come back good & the alignment wrong. This is all I'm saying. I believe my example stands if consideration is made that the tech does not follow correct procedure. A lot of techs must not follow correct procedures because many people seem to have problems with alignments.

Brad123D · #13 05-08-2003, 12:32 AM

I recently "straightened up"(with new tires) a vehicle with the off center symptoms you describe. Have you checked your tires? You could swap the fronts side to side and do a brief drive to see if anything changes. If it is the tires it should change the steering wheel align on a straight. I think I would not run the tires that way... only for a test.

#14 05-08-2003, 08:09 AM

Yes, that's right, toe will not be correct at 30 degrees. In fact, it should NOT be equal at 30 Degrees. This relates to the "Ackerman Theory."

Think about it, when you are turning, the inside wheel is turning at a different radius than the outside wheel. If this were not compensated for, your tires would scrub like crazy every time you turned.

The Ackerman Theory involves an imaginary line from the center of the line going between the two rear wheels. The line stretches from that point to the steering pivot(ball joints or king pin.) Perfectly aligned on this imaginary line should be the center of the outer tie rod end. This is all, of course, with the front wheels straight. If this line is correct, then the front wheels will turn at different, but correct radii and prevent tire scrub when turning. This is not something you can adjust, it is designed into your car.

The toe is set to zero, and the wheel centered, by whatever means, preferably so that the steering wheel is straight and at the center point of the steering box action. The box is designed to be tight at the center, but has a little more slack away from center. With the steering box and steering wheel centered and toe set, loosen the tie rod sleeve locks and turn both tie rods equal amounts in the same direction to point wheels straight forward. Without fancy alignment equipment, this will involve a little cut and try and then test drive. Once the wheel is straight, recheck toe to be thorough.

Good luck,

leathermang · #15 05-08-2003, 11:59 AM

Thanks Larry,, that is what I was talking about.. I remember the concept from highschool automechanics class but did not remember the name....
Now, if we were dealing with center pivot buggy front ends... you could turn it 90 degrees and it would still read the same...

Brad is also correct that tires alone , even with everything else right,can cause pulling....