How accurate a wheel alignment machines
Discussion
In October, I had my Cayman aligned at a local garage with front camber set to - 2.3 on both sides (it has adjustable arms). This was both sides maxed out (fully inboard) in the slots
Yesterday I had it realigned at a different place (a tuner/racecar prep place) and the before measurement for the front was - 2.3 on one side and - 1.7 on the other.
They have now equalised both sides to - 1.7 (which was what I wanted) by moving one of the struts 3/4 of the way outboard.
Given that nothing had changed, surely the before measurements should have been comparable between October and now. The car has new suspension and is fully poly bushed so I don't think bush wear would be the answer.
The rear was far closer and just required a little tweak.
So my question is, how accurate/repeatable are wheel alignments?
Yesterday I had it realigned at a different place (a tuner/racecar prep place) and the before measurement for the front was - 2.3 on one side and - 1.7 on the other.
They have now equalised both sides to - 1.7 (which was what I wanted) by moving one of the struts 3/4 of the way outboard.
Given that nothing had changed, surely the before measurements should have been comparable between October and now. The car has new suspension and is fully poly bushed so I don't think bush wear would be the answer.
The rear was far closer and just required a little tweak.
So my question is, how accurate/repeatable are wheel alignments?
It's possible to mess them up by leaving some preload in the suspension bushes when positioning the car, so the geometry that's measured doesn't reflect the normal running geometry. Anywhere competent should be aware of that though.
Hard to tell whether either/both measurements are accurate, but the later measurements seem to be suggesting one side is substantially different to the other. So presumably they're claiming that either the chassis or some suspension component is bent.
Hard to tell whether either/both measurements are accurate, but the later measurements seem to be suggesting one side is substantially different to the other. So presumably they're claiming that either the chassis or some suspension component is bent.
GreenV8S said:
Hard to tell whether either/both measurements are accurate, but the later measurements seem to be suggesting one side is substantially different to the other. So presumably they're claiming that either the chassis or some suspension component is bent.
Must of the suspension has been changed (shocks, arms, mounts etc) and the chassis itself has no signs of damage (factory welds, seam sealer, primer etc etc) so I'm assuming that either the upright is bent or the subframe needs adjusting (you have to drop the subframe to do various jobs and it is possible to screw up the alignment) At the end of the day it doesn't have to be "perfect", just decent enough.
A variety of machines can be damaged or out of adjustment or in need of calibration, the technicians who work on these machines may be a different level of competence.
One measurement may be in degrees the other may be in hours and minutes.
It carries on.
Basically it's very, very rare you can go from machine to machine and get repeatable results.
I have a rough idea of what I like my alignment to be , but the truth is, if it drives nicely, goes straight and the tyres wear evenly then I don't care.
Also, did you have the car re-aligned after fitting the new bushes / suspension?
Any work will impact the alignment. I have Polybushes fitted to my 320d and when it went to get aligned, I went from a neutral toe out at the front to a total of 23.5 degrees!
Any time any suspension part gets changed I get the car aligned, as such I try and group suspension work into a big single piece of work to not have to get the car aligned multiple times.
A variety of machines can be damaged or out of adjustment or in need of calibration, the technicians who work on these machines may be a different level of competence.
One measurement may be in degrees the other may be in hours and minutes.
It carries on.
Basically it's very, very rare you can go from machine to machine and get repeatable results.
I have a rough idea of what I like my alignment to be , but the truth is, if it drives nicely, goes straight and the tyres wear evenly then I don't care.
Also, did you have the car re-aligned after fitting the new bushes / suspension?
Any work will impact the alignment. I have Polybushes fitted to my 320d and when it went to get aligned, I went from a neutral toe out at the front to a total of 23.5 degrees!
Any time any suspension part gets changed I get the car aligned, as such I try and group suspension work into a big single piece of work to not have to get the car aligned multiple times.
Hi,
All suspension work was done at the same time (before the first alignment) and nothing was changed between October and yesterday.
I simply wanted to reduce the front camber a little to provide a better compromise between track and road.
This is why I find it confusing to have such different numbers between the two alignments
All suspension work was done at the same time (before the first alignment) and nothing was changed between October and yesterday.
I simply wanted to reduce the front camber a little to provide a better compromise between track and road.
This is why I find it confusing to have such different numbers between the two alignments
LennyM1984 said:
Hi,
All suspension work was done at the same time (before the first alignment) and nothing was changed between October and yesterday.
I simply wanted to reduce the front camber a little to provide a better compromise between track and road.
This is why I find it confusing to have such different numbers between the two alignments
A kerb or pot hole could potentially move things slightly, especially if things aren't quite as tight as they should be.All suspension work was done at the same time (before the first alignment) and nothing was changed between October and yesterday.
I simply wanted to reduce the front camber a little to provide a better compromise between track and road.
This is why I find it confusing to have such different numbers between the two alignments
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