[tadaska]

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There is a big difference between the camber angles on my front wheels. Looks like it has been attempted to minimise it by moving top mounts in opposite directions but there was still some difference.

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When I bought the car and took it for a wheel alignment:

Before:

Left: -0.49 Right: -0.08

After:

Left: -0.47 Right: -0.08

I have now fitted M3 lower control arms and pushed both upper mounts towards the engine all the way:

Before:

Left: -1.54 Right: -0.49

After:

Left: -1.44 Right: -0.28

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Any ideas why it is so lopsided? Could it be that the front subframe is not perfectly in the middle?

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[therealdb1]

Perhaps the previous owner raced it on oval circuits!
Do you have a broken coil spring or bent control arm or a collapsed bush?
Whatever the reason there is no point modifying the suspension until it is balanced because you will just make the problem worse as your figures show.
I guess by replacing the arms you have ruled those out but you can see it is skewed as the M3 arms have added 1 degree of negative camber to the left but less than half of that to the right.
I wouldn't think there should be more than about 30 minutes difference from side to side.
What are your caster angles like? It might give you an idea where to start looking.

[tadaska]

I just did a full frontal refresh - arms and tie-rods (forgot the drop-links when ordered parts last years...). I didn't see any damage to the subframe, but I wasn't looking tbh.

Caster was on the first alignment: L 6.27 R 6.44

Caster at this alignment: L 7.06 R 7.13

It has shifted by the looks of it. I personally have no idea what affects caster...

Edit: no problems with the springs.

[therealdb1]

The caster looks fairly well balanced side to side so whatever is causing the problem is only significantly affecting camber.

What if you temporarily refit the camber pins that were removed before? At least then you will know that the top mounts are in the right place and any discrepancy when you measure the camber must be at the bottom.
At the moment you do not know if it is top or bottom where the problem lies.

[tadaska]

Originally Posted by therealdb1

What if you temporarily refit the camber pins that were removed before? At least then you will know that the top mounts are in the right place and any discrepancy when you measure the camber must be at the bottom.
At the moment you do not know if it is top or bottom where the problem lies.

I don't know... that would probably mean spending another £60 on a new wheel alignment. And since both mounts are pushed all the way in that kind of means the problem is bellow? Of course I could minimise the difference by pushing the left one all the way out. But I'd rather add more negative camber on the right than lose it on the left. What I have now is good for the roundabouts right? Maybe they make them that way on purpose for the British market?

Do front subframes have play in them when bolts are loosened? Or could it be affected by the strut mounting at the bottom?

[therealdb1]

Originally Posted by tadaska

both mounts are pushed all the way in

That is my point, where the top mounts are at the moment is pure guesswork. There is no guarantee that the bolt slots match on either side of the car especially since we suspect that someone has already been in there messing about with the alignment. The camber pins were installed at manufacture so it was simple to get the strut in the right place without having to measure anything. Why not use what you already have?

Ultimately yes you will need to spend on another professional alignment but while you are trying to find the cause of your discrepancy you could make up a simple camber gauge which will be accurate enough to get you close.

I once lowered a 24v Vauxhall Senator (why? another story!) but I used a straight edge across the wheel rim, and a spirit level to get the vertical. Then you can use a protractor to directly measure the camber angle wheel rim to vertical or do as I did and make simple linear measurements top and bottom of the rim from the vertical spirit level and trigonometry to calculate the angle. Once I had finished the job I got a 4 wheel alignment done and no further camber adjustment was needed.

I must mention though, if you use the spirit level technique, the car needs to be parked on a flat horizontal surface like a garage floor. If you try and do it in a normal road the camber of the road will skew your measurements.