Car pulling to left after alignment

[Leafsrule531]

Hi - I need some advice from the experts here. My car (e46 m3 coupe) is pulling hard to the left when driving on the highway. I recently got an alignment done at a well known shop and I’ve attached the specs of what did. According to them the alignment is perfect and according to spec but the car is still pulling to the left. I have kw coilovers v2 and I’ve checked the tire pressure on all 4 and they are fine as well. What do you think the issue could be ? I don’t know much about alignments but could they have done it incorrectly ?

[Slideways]

There is 1 degree difference in camber on the front. Do you have camber plates and is the ride height equal on both sides?

[Leafsrule531]

There is 1 degree difference in camber on the front. Do you have camber plates and is the ride height equal on both sides?

Unfortunately I don't have camber plates. Do you recommend I get them ? What's the advantage of having em ? I have coilovers so in theory the height should be equal but I noticed the rear left is lower than the rear right so I need to adjust that. Would that cause such a strong pull to the left ?

[Tbonem3]

Perfect alignent with -.9 & -1.9 camber?

Maybe one of your strut mount's pins are pullled. With pulled pins, stock hats, when the car is lowered, can get to about -1.8 in my experience.

Height matters because camber is dynamic and goes negative, to a point, as the wheel goes further up into its arc (into the fender). I don't see how one side could be that much higher than the other, though. Measure the distance between bottom spring perch of coilover to strut body or swaybar tab and equalize them.

Caster also affects pull to one side. Ideally, to an alignment tech, a slight variance would have the car pull left slightly to "fight" the crowning on streets.

[Leafsrule531]

I just measured the height from the bottom of the rim to the fender. All 3 wheels are 24 inches but the left rear wheel is 23 inches. Is that what's causing my car to pull to the left ? I have KW v2 coilovers so presumably I could fix those but I believe it's fairly difficult.

[bmwfnatic]

The one degree difference in camber is interesting to say the least, if the alignment pins are still in place then that’s even more concerning, perhaps an incorrectly assembled component, a previous love tap or damage to the strut tower itself.

Did the car always pull to the left? Or only since the alignment, sometimes they mess up on centering the steering wheel because they do it too quickly.

Furthermore, from my own experience, I once chased a pull to the left that didn’t make much sense because I had just replaced my entire front suspension, but it turned out to be my totally shot RTAB’s steering the car from the rear end, probably not the issue here but always worth to inspect.

[Nate047]

I would take it back and ask them why that is the best result they can get. If they can't tell you, or give you any grief about asking, I would go to a different shop. Big part of what makes a good alignment shop is them knowing or at least being able to help diagnose what's wrong.

[bigjae46]

This is why I do my own alignments...

The first measurement that's taken is caster when you setup the car on a laser alignment rack. The front wheels are turned +/- 15 degrees and then records the caster reading. The tech will then need to start with the steering wheel centered and then re-center the steering wheel to make camber and then toe adjustments. 99.9% of techs eyeball the steering wheel being on center.

I'm 95% sure the tech didn't center the steering wheel which would explain the difference in caster and camber left to right on the front axle.

If it is a Hunter alignment rack, the BMW approved model will be able to take a SZL reading to make sure the steering rack is centered so then you get an equal left/right caster reading.

I do my own alignments on a smart string kit. I use INPA to take a SZL reading. I've done 3 cars so far...all have been dead straight. I used a Hunter rack for awhile. I will admit, I almost always had to align it twice. I am extremely picky and sensitive with the alignment so I would probably be ok on the first try for most people. I even talked to the guy that Hunter sends out to calibrate the rack.

String alignment > laser alignment