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On Saturday firestone did a wheel alignment for my 1990 Subaru legacy. I paid the dollars. later that afternoon I took the car for a drive down the southern motorway (akld) testing the wheel alignment thinking it should now run in a straight line. the car gradually steered it's way to the left. I tested it again, and it did the same. When questioned this morning, Firestone state the alignment was done on a machine set to the type of car/model, etc, it was also road tested (street) after it was aligned, all seemed well.
They are unable to offer an explanation why the car is not running in a straight line. Four new tyres (six months old), CV joints replaced about 8 months ago. I am returning the car tomorrow for a further comment from Firestone - but need some help as to why its not running straight - I can't accept the machine as being their answer so I'm asking you.

If the car gradually drifts left as per the camber of the road, then this may be normal on a RHD car, driving on the left.
If it's at all possible, find a long wide one way street and try driving on the right side of the road - where you may find the car drifts right, which would also be normal.
If the car is pulling left on a perfectly flat surface with no camber, the alignment may not right and should be re-checked. However, it's almost impossible to find any road surface with no camber at all.

thank you for your reply - kindly note the car is 4WD station wagon - whether this influences its gradual pull leftwards - I'm unsure.

I purchased the car some 12 years ago from an retired farmer who bought it brand new from the dealership- the pull is not normal, always sat perfectly on the road - a pleasure to drive, taking it on our summer road trips....killer with no air conditioning, but that's all part of the fun.

if you have any further thoughts - would appreciate.

The things which can really cause this are alignment, tyres, tyre pressures and suspension/steering.
If tyres are all in good condition with the same size, type etc of tyre all round, it's unlikely to be tyres.
Uneven tyre pressures will cause this symptom, so make sure they're all even (sorry if this sounds like an obvious one, but needs mentioning, just in case).
Suspension height to be even all round with no saggy springs or bent steering rods or components etc.
Then of course, this brings us back to wheel alignment - including toe, caster and camber.
Sorry I can't add much else. Hopefully the alignment shop may find the problem this time.

hi there,

car returned to Firestone where they road tested, agreed it was veering to the left. I told them the criteria set on the machine incorrect for type and year of car. after a meaningful discussion - another wheel alignment performed using the correct criteria, further adjustments made, road tested and air pressure checked. car runs better however does go to the left. they could not detect any bent / sagging rods. where do I take it for suspension / further investigation. cheers.

Perhaps the Subaru dealer may be able to shed some light on this. If the alignment is within specification in all respects, tyre pressures are correct, nothing is bent or damaged, no binding brakes etc, I can't see why the car would pull left.
If it's definitely pulling left on a perfectly flat surface (ie; not due to road camber), the only other avenue is really the main dealer who has all the factory information and technical data.

value your feedback, agreeing to comments about referring car to a dealership.

Have a great week.