Car drifts to the right after new tires and alignment

mercedes-benz
sl-class

#1

my car tracked straight until I put on 4 new Michlein Pilot Sport A/S tires. I took it to Mercedes for a 4 wheel alignment. Still drifted right. Tire store pit on 2 new front tires. Still drifts right. Mercedes says it must be the tires. What do I do?


#2

Rotate the tires to see if the drift changes.


#3

Thanks for your reply. Is it OK to reverse the front tires even if they are directional.
As you know the fronts and backs are staggered. If I reverse the fronts and it still drifts right does that confirm that the alignment is not on spec?


#4

Alignment specifications are not edicts from Olympus. My ‘from the hip’ guess on this situation is the dealer is standing fast on his “by the book” specifications as read on his equipment while the tire dealer has done all he can to prove that the tires are not defective, leaving you in the Catch 22. Find a locally owned alignment shop and explain the situation. He may tell you more tales of similar problems than you want to hear. If he’s good he’ll drive the car before and after aligning it.


#5

Thanks very much Rod. I am thinking since I already paid $190.00 to the MB dealer to have him drive the car with me in it. if you take your hands off of the sterring wheel regardless of the pitch of the road you can see that the steering wheel cantors very slightly to the right.
I appreciate your response. tough to spend $1,500.00 on tires and $200.00 on alignment and not have the car drive straight.


#6

I agree with Rod. I have experience with the Michelin Pilot tires and they are very good tires. I recommend them all the time. The alignment was botched by the dealership.


#7

I’ve fixed this problem by rotating the front tires side to side. In your case, you’re going to have dismount and remount the tires since they’re directional.

Ed B.


#8

Any chance the alignment is off?
If you have the printout of the alignment could you check or post the specs on the alignment? (especially as regards caster and to a lesser extent, camber)

Hopefully the track (or thrust angle) is correct also. (something that can kind of get overlooked)

Pulling can certainly be a sign of tire bias but having it do this on two sets of new tires sounds odd at least. I’d rotate the 2 front ones side to side and if the problem is still there my feeling is that an alignment problem exists. (again, look at those caster specs very closely)


#9

Simple test: Swap the front tires side to side.

If the drift completely chnages direction, the problem 100% in the tires - a property called conicity.

If the drift doesn’t change at all, then the problem is 100% in the vehicle - likely alignment.

If the drift disappears, or is substantially changed (other than a 100% change in direction), then both the tires and the vehicle are contibuting to the situation.


#10

It is entirely possible that the alignment was done poorly, either due to operator error or equipment out of calibration. My bet is on either of those, not the tires. Another possibility is that a car jockey at the dealership hit a curb too hard and does not want to tell anyone.


#11

You don’t show how or old or new your MB is. However just a quick check you can do is check the air pressure in the tires to hopefully triple confirm at this point.


#12

Don’t put too much into the position of the steering wheel. What likely happened is they drove onto the alignment rack with the wheel off-centered. Then they aligned the wheels, which meant that they set the toe-in relative to that position of the steering wheel. If they did the alignment properly, the car should drive straight with no drifting when you let go of the wheel on a flat (that point is critical) road. The wheel can look off-center, but its generally more aesthetic than it is a serious concern. I’ve had that happen before, and when I got annoyed by it, I simply loosened the jam nuts on both outer tie rod ends and gave the inner tie rod on each side exactly one turn (being careful to shorten one side and lengthen the other) and retightened the jam nuts - that solved the steering wheel issue so it was centered, but it didn’t affect the actual wheel alignment.


#13

Capri, I seem to recall you saying in a past thread that there are some Road Force Balancing machines that will detect conicity. That might be the best way of determining of that’s the cause or eliminating it if it isn’t, especially since they’re directional tires.

Personally, I suspect the alignment. A steering wheel cantered off-center after an alignment is a sign of an improper alignment. The first thing that should be done is to be sure the car and steering wheel are straight before beginning adjustments. Doing otherwise results in the steering components not ending up in the centers of their travel ranges and can end up with a car “crabbing” down the road, a condition not as uncommon as it should be. I saw one just yesterday. And that can also cause drifting to one side.


#14

My reply to CapriRacer (see the post) makes me want to suggest that you have a friend follow you down the highway and see if your MB is traveling at an angle, known as “crabbing”. If it is, that is an absolute sign that they did a bad alignment.


#15

This is because your front wheel is out of balance or either check all 4 wheels. Check the air pressure in tires. if the problem is still there then kindly check alignment.
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