To measure camber, you need to measure the angle of the line between the top of the wheel rim and the bottom of the wheel rim and compare this to the vertical. I must stress here that this only works if your car is on a level – horizontal – surface. You could use a camber gauge for this. I bought a little bubble camber gauge for this job but I didn't think it was very good. The magnetic base of my bought camber gauge wasn't really of a size that was compatible with the end of the front axle – I couldn't get consistent reliable measurements so I made the following contraption (idea came from another forum
http://www.pistonheads.com/gassing/topic.asp?h=0&t=258944).
For this you need to find two set squares with millimetre ruler scales and another set square that will be used to position the gauge up against the rim. If you have them use three set squares of equal length. I attached the three set squares to a straight edge that just happened to be a spirit level (the vertical level sight provided useful confirmation). Attach two of these set squares to the straight edge at a distance apart that allows you to make contact with the top and bottom of the rim without touching the tyre. The upper set square needs to be one of the set squares with the millimetre scale. Then attach your third set square above the set square that makes contact with the upper part of the rim at a distance of 573mm. I then tied a plumb bob to the top set square.
When the straight edge is vertical the distance at which the top of the plumb bob is tied to the top set square will be the same distance at which the string of the plumb bob will touch the bottom set square. If you tilt the straight edge you can get the string to move a distance along the scale of the bottom set square. Ten millimetres movement on the bottom scale is equivalent to a change in angle of one degree (so long as you have a distance of 573mm between the two set squares).
WARNING using a DIY camber gauge like this can seriously scratch your car – be careful!
Now that you've made your camber gauge you can set to work measuring your camber. You can also measure rear wheel camber but on a W123 and W126 there is nothing to adjust. Here are instructions for measurement of front wheel camber:-
1.The FSM says you need to set the toe in / out to zero degrees – so use step 7 above to do so.
2.REMOVE THE SPREADER BAR
3.Hold your camber gauge up against your rim and make your measurement
4.To adjust the camber you need to loosen the nut on the LCA eccentric bolt mount and turn the bolt to a new position. Tighten the nut – tight - but not to the specified torque.
5.Re-measure the camber and adjust if necessary.
6.Next measure the camber on the other front wheel.
7.Adjust if necessary.
8.If you have made adjustments is now quite likely that your toe in / out is completely out of alignment so go back through the process from step 1 until you do not need to make any further adjustments.
You should have to make smaller and smaller adjustments as you go through this process. If you think you suddenly have to make a large adjustment – stop and think about it. Where did you go wrong? Are you sure you want to do that? Do you really want to undo all the work you've done so far?
For my W123 the camber setting is 0 degrees +10 minutes / - 20 minutes – so it is essentially zero degrees. With the DIY camber gauge it is very easy to achieve this.