I took my 1995 530i in for a wheel alignment. (It drifts to the right) The local told me there was no caster or camber adjustment. How are the wheels on this model aligned? And is a 4-wheel alignment required??
The only adjustable is the toe. If caster or camber is out it needs to be pulled on a frame rack. Yes, you should have a trust angle alignment done.
Well, you jdo have 4-wheel independent suspension, so, yes it could need a 4 wheel alignment.
I can't imagine that there is no Caster or Camber adjustments. Given the construction of the suspension system, you can be sure there are adjustments for all three planes of each corner.
CASTER There is an imaginary line that runs through the center of the upper and lower ball joints and the spindle that the tire spins around. These three points make a plane that is called caster angle. I am not sure what the rear caster angle should be, but I assume it should be zero, that is it should be prefectly perpendicular to the ground. The caster angle of the front tires should be leaning towards the rear of the car.
CAMBER Camber angle is the angle at which the tires hit the road. In a solid axle kind of car, this angle is zero, but in an independent suspension, the engineers can design this angle specifically for the particular car. The front tires typically have a zero angle, or near zero, while the rear tires can have a more pronounced angle. Greater camber angles will provide stability in cornering, but will have increased tire wear on the inside edges. For a private passenger car, I would suggest that the best angle is zero for all four tires, but I am almost certain that some cars will have a definite camber angle that can be seen if one bothered to look.
TOE IN/OUT This is an adjustment that is generally only found on the front tires. It defines how parallel the tire on the left is with the tire on the right. The rear tires could have a toe in/out angle, but it will be zero. The rear tires should always be parallel, but the way the independent suspension is built, there could be an adjustable setting that can be knocked out of adjustment, perhaps by striking a curb or pot hole. I can't address the fact that your BMW has or does not have an adjustable rear toe in/out, but there is no particular reason that it couldn't have one. It wouldn't be very useful, but it could still be there. Perhaps toe in/out on the rear axle has a different name that has escaped me at the moment.
To recap, Caster is the angle forward or backward that the tires are, Camber is the angle that the tires strike the ground, and Toe in/out is how parallel the right and left side tires are to each other. A 4-wheel alignment will also align the front and rear tires so they are on the same track. You should have all three adjustments on the front tires, and have at least caster and camber on the rear.
No, actually what he was told is correct. There is no means of adjusting either caster or camber designed into these cars. That does not mean that it can't be done. First, you put the car on an alignment rack to see if it is out of tolerance. Then, only if needed, you would have to add various shims or offset bushings or other doo-dads to allow some adjustability. But in the stock form, there are no eccentrics or other adjustments provided.
It's actually kind of nice that you can slap in all new suspension components and the only alignment that really needs to be done is the toe-in.
-Fred W
Wow! That's amazing that there are no adjustments for caster or camber in an independent suspension. I guess I need to spend more time under my car so I'd know this sort of stuff. I would have thunk that the adjustments would be done by way of eccentrics as opposed to shims, but if you say there are no adjustments, then I am not going to argue the point.
I did a pretty good job of explaining the adjustments thought, didn't I?
Thanks, guys. I should have checked here first. Maybe the dealer quote at $150.00 wasn't too far off.
It's still worthwhile on a car with a rigid rear axle, since the location of these can also be out through damage or wear.
Can't see why. You can't adjust many of the engineering tolerances on the rest of the car apart from through replacement of parts, so why should the suspension be different?
That's only for a check. And it may not show the reason for pulling to one side.
If you're certain the tyres are all worn the same and at the correct pressures - don't laugh - then it's likely to be worn or damaged bushes or other components which can only be replaced - not adjusted.
Have you had the car since the steering was ok and this fault has developed - or have you just bought it?
Yes, indeed you did. ;-)
-Fred W
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