How well should a car track? What causes pulling?

[T.C.]

My car pulls to the right. If I'm on the highway and I let go of the steering wheel, I'll be in the next lane about 4 seconds later. Is this typical? Good? Bad? I've seen lots of posts related to pulling and alignment, but I can't find any mention of what constitutes acceptable performance and what should be regarded as a problem.

Yesterday, I had four new tires put on the car and a wheel alignment performed. Those changes made no difference; the car pulls to the right about the same as before. What, besides tires and alignment, can cause a car to pull to the right?

The car is a 2003 Nissan Xterra with 4WD.

-TC

[gmtech1]

Do you have the alignment print out? If so, post the readings.

[T.C.]

This is what the alignment printout says:

  Front Left      Actual  Before  Specified Range
  -----------------------------------------------
  Camber           0.1    -0.2     0.1  to  1.1
  Caster           1.9     1.9     1.7  to  2.7
  Toe              0.14   -0.10    0.13 to  0.21
  SAI             10.1    10.5    10.3  to 11.3
  Included Angle  10.2    10.2    10.4  to 12.4
   
   
  Front Right     Actual  Before  Specified Range
  -----------------------------------------------
  Camber           0.8     0.8     0.1  to  1.1
  Caster           2.2     2.2     1.7  to  2.7
  Toe              0.19   -0.18    0.13 to  0.21
  SAI             10.2    10.2    10.3  to 11.3
  Included Angle  11.0    11.0    10.4  to 12.4
   
   
  Front           Actual  Before  Specified Range
  -----------------------------------------------
  Cross Camber    -0.7    -1.0    -0.8  to 0.8
  Cross Caster    -0.3    -0.3    -0.8  to 0.8
  Cross SAI       -0.1     0.2
  Total Toe        0.33   -0.27    0.25 to 0.42
   
   
  Rear Left       Actual  Before
  ------------------------------
  Camber          -0.2    -0.1
  Toe              0.12    0.11
   
   
  Rear Right      Actual  Before
  ------------------------------
  Camber           0.0     0.0
  Toe              0.00    0.01
   
   
  Rear            Actual  Before
  ------------------------------
  Cross Camber    -0.2    -0.1
  Total Toe        0.12    0.12
  Thrust Angle     0.06    0.05

[gmtech1]

The left camber at 0.1 with the right side at 0.8 will cause the pull to the right. I would have the alignmnet shop set it to match the left side. The cross camber should be closer to 0.The caster being a little lower on the left should help it drive straight on a road crown when the camber problem is corrected. So many people think that just because a number is "within specs", that the car will drive ok. A guy needs to know how to read the printouts and understand what they mean and how the car will react to them.

[T.C.]

Thank you for the analysis.

Can you help me put this into perspective? How much of a pull is cause for concern?

Also, how much control does an alignment shop have over the calibration? Should they be able to center my cross camber to within 0.1 degrees? Or is +/- 0.7 degrees a decent job?

-TC

[gmtech1]

I obviously can't feel the pull, so it's up to you what you think is excessive. You can't expect the car to drive straight without driver input for miles. If you are concerned with it, have the changes made and you should be able to feel the difference. I believe your truck is fully adjustable with eccentric cams in the lower control arm. If this is the case, the alignment shop should be able to get it set dead on, assuming there is no excessive wear in bushings, bearings, ect...and no damaged parts.

Cross camber is simply the difference between the two sides. The (-) sign indicates more positive camber on the right. The truck will pull to the side with the greater positive camber and/or the side with the least amount of caster.

[vgames33]

Your X-terra does have cams for caster and camber and should be fully adjustable (within reason). They're always rusted solid up here, but I doubt that's the issue given your location. I accept under 0.4 degrees of cross caster/camber for my own work.

To help visualize, negative camber is when the top of the tire leans to the center of the vehicle. Positive camber is the opposite. The more positive value on the FR can cause a pull to the right.

You could also have a tire pull, even with new tires. Typically the car will track fine until you let go of the wheel. Crossing tires side to side should fix it. Dragging brakes can also cause a pull.

[dharris973303]

i did lots and lots of alignments.

one time i had a car come in with a "pull" it was alignd IN SPEC (nothing wrong), test drove it, still pulld.

i actually atempted, (by sugested by me boss) to counter the camber to offset the pull. (angle the wheels inproperly)

it still pulled.

turns out another reason for pull, and problly yours too, is the rack has lost a seal, as in rack an pinion steering. you're probly gonna need a new rack put in to fix it.

a way to confirm this.... jack the front off the ground. (jack stands) start it and the sterring pump will feed the rack. if the tires turn you've got a leaking seal.


other unmentiond items are bent body, bent suspension parts

[T.C.]

Thanks for the advice. I took my car back to the shop and had a talk with the manager. He gave me a complicated story about how the cross camber wasn't the problem, and they would have to adjust the toe, and this is more of an art than a science, etc. I think it was all BS. The technician who did the work seemed to be competent, however, because he reduced the cross camber from -0.7 to -0.4, and now the pull is proportionately improved (i.e. it's about half as bad). I don't know if -0.4 is the best they can do, or if they just didn't try to do better. I don't think I'll go back to that same place for my next alignment.

-TC