Hello guys, 2008 S40, 100k miles.
Car pulls left without any obvious reason.
Coasting, braking, accelerating, anytime it does.

It goes straight if wheel is turned right a bit(3 deg)
Goes straight hands off, but steer keeps right a bit (3 deg again)
Rear tire set changed 2 weeks ago, noticeable after that.

Shop says alignment is good, they'd test-driven it, crossed the tires on the front
Still pulls to same side.

They say it's probably tire problem (front set 6 yo), recommended a new set, I don't understand it cause it's same even after rotation.
Anyway, I accepted it. (Old set anyway)


My guesses are :

1. Front tyres are assymetric, and it's not fitted well. ( the "looks" from the front is not balanced )

2. I've had an accident, 1 month ago. Hit the car on the front with 3mph. (No visible damage on my car but front car had its bumper broken)

3. Mounts are probably worn, vibration increased last 2 years. No visible damage on mounts, and it's acceptable, I haven't changed it.


What do you think? Is it possible?

If not what would cause it?

 

To rule out the tires you could put the new ones from the rear onto the front.

Have you checked the brake pads? A sticking brake caliper or collapsed brake hose can cause a pull to one side at all times. The pad would be worn noticeably more than the right.

Did they measure the alignment? i.e. put it on an alignment rack?

 

Yes. The pads are good.
And yes, they have a big system with some kind of infrared reflection plates set all 4 tyres, ive also seen the monitor shows green( which says ok) too. Another think of mine is that they've probably aligned it without steering centered

 

does the steering feel notchy or change as you turn (suggests worn control arm or end link bushings)? Any clunks over bumps (strut mounts etc)?

I'd probably start by going to another alignment shop - they should have centered the wheel and it almost sounds like the car may be "dog legging" (needing a thrust angle alignment). Of course tires as note are always suspect #1 (most tire's rubber gets hard after 5 years so even though they have treadlife, they are not as compliant as a new tire). I'd +1 on doing the front/rear rotation to see if anything changes and do the cursory check for brake drag (particularly on the rears with the e-brake set up

 

You can also check for a tire pull by swapping the front tires. Assuming they are non-directional tires, put the right on the left and left on the right. If the car pulls the opposite direction then it is the tires.

 

Do you have a print out of the alignment measurements? Just because its green doesn't mean it can't pull.

 

I'm afraid there's nothing wrong on bushings and arms.

Yes, I'd see if they fix it up on this Friday, by replacing worn tyres.
I think they won't, and refunds on me anyway

 

They tried changing tyres on the front, it's still same, (same direction also.)
Strange, right?
Could it be transmission problem?

 

Good idea, I'm going to ask them one and post it Friday, if it's not fixed.

 

The new tire set settled on front,
They seem to have new alignment.

Problem is fixed..But I don't get it.
What would have caused this?
Here's the Alignment data.

Front
Camber (Target : -0.60 deg)
Before L-0.64 R-1.07
After L-0.76 R-0.81

Caster (T : 3.60deg)
Before L3.09 R3.28
After L 3.16 R3.37

Toe (T : 1.3mm ±1.3mm(not deg, millimeters)
Before L0.3mm R1.3mm
After L1.4mm R1.2mm

Rear
​Camber T : -1.52deg
Before L-2.08 R-2.47
After L-2.47 R-2.28

Toe T : 1.9mm±1.3mm
Before L3.1mm R1.8mm
After L1.8mm R1.5mm

 

So you replaced the front tires? And they aligned it again and those are the measurements? Or were those from the last alignment?

 

Yes. I replaced front tires.
They realigned it, it's the latest data.

So, the 'before' data is 'after' the last alignment.

 

Looks like the original alignment was not spot on and its quite possible the old tires simply accentuated the rear left toe in. My experience on my 2000 S40 and my VW CC (which BTW is notoriously difficult on alignments - just read some of the comments on how they eat up tires) is that different models have a "sweet spot" that may not be dead center in the middle of the spec. On one occasion I got a cheap alignment from the tire shop for the S40 that looked good on paper but felt off. Had the alignment redone at the dealer and their small changes made the car feel right...

 

Yeah, the alignment was clearly off. Glad it's fixed.

 

interesting story. I'm surprised how a well aligned car can go one side.

 

Rear toe maybe?
The alignment had been in specs , I'm surprised , it could still go biased.

 

Like I said, just because it is in spec does not mean it can't pull.

Toe needs to be both in spec and equal.

 

Thanks for the info, I'll keep that in mind, help the others in the future.