Hitting a curb can cause many problems.. Here's some possible symptons that may be creating the problem.. Let me know if u find any. Im just giving possible causes of the top of my head that may cause your problem =) Tyre Pressures!!!!! Have you checked the tyre pressure since hitting the curb? You may have cracked the alloy or damaged the tyre which has cause loss of air. If it was the passenger side u hit, and its lost air it will cause drag and make it veer to the left. If pressures, tracking and alingment is all good (as they say) then i would start by jacking the car up so the wheel that hit the curb is off the ground. Spin it round and look for any warp in the alloy, listening for grinding noises, and feel for any resistance during a full turn. ( if resistance u may have a sticky caliper piston ) Next with one hand at the top and one underneath, see if the wheel is solid or rocks feeling as though the nuts a loose ( this could be a dodgy wheel bearing ) If everything seems fine next take the wheel off! Check the lower wishbone, see if its bent/twisted. At the end of the wishbone nearest you you'll see a balljoint that the hub is bolted to. Using a form of a pry bar look for exessive movement. This ball joint should be stiff as hell! Next check half way down the wishbone.. You'll see the drop link attached from the wishbone to te anti roll bar. Are the bushes good? Is it bent? Check your suspension arm.. Does it look bent? Is it tightly bolted to the top of the hub? Open the bonnet and find your top mounts.. Bounce the car... Are any of the 3 bolts loosing contact with the car? Also compare the side in question's top mount holder to the other side.. Are they the same shape? ( with my rock hard suspension mine were bent as hell ) Its now 4:00am and my minds gone blank as what to suggest next lol If u find the problem please let me know =) always interested to hear as this could inprove knowledge. Cheers