Yesterday I bumped my left wheel on a pavement, due to an understeering after accelerating (my bad). I smashed it quite good and I was certain the alignment was off, so I did some tests. No tire squeeking on turns, no high speed vibration, although I noticed the car goes just a little to the left when driving straight. But the most intriguing thing is the fact, when I steer a little (about 2-3cm) from the straight position of the wheel, at low speeds (like 20-40km/h) I can feel a broad and heavy oscillation in my hands, about 1-3hz? I play with the wheel when going straight, tilting it a bit to the left and right, and always feel this oscillation. This behaviour seems to stop over 70-80km/h. What could this be?
You would best be advised not to drive the vehicle before you have had it inspected for any damage by a mechanic or tyre centre. Your reported observation on the change you have noticed only goes to show that something is damaged, and it may be a case of it about to completely break. Have it inspected.
Check the tire for play.
- Secure the car on a jackstand near the corner you want to check.
- Grab the tire on the left and right and alternate pushing/pulling.
- Do the same top to bottom.
Top to bottom is usually ball-joint. Left to right is sometimes tie rod and sometimes wheel bearing. The important thing is that if there's play, something is wrong and needs further inspection.
I have a similar symptom on my car when the suspension bottom ball joints wear out: at some speeds, when turning just slightly, wheel wobble ensues, and I can feel it through the steering wheel. Sometimes it's quite pronounced.
This happens quite often because my car is 40 years old (Triumph Stag) but has similar front suspension to modern cars. It just wears a bit more quickly.
What happens is as the bottom ball joint of the suspension strut wears, it allows play which allows the wheel to 'castor' a little bit, but the nature of the geometry is such that it ends up wobbling from one end of its play to the other. This can only happen when the suspension alignment is fairly relaxed, which for most cars is when slightly turning a corner (owing to various alignments being [deliberately] not quite central).
This also happens if the track rod end joint (end of steering rack) wears, but less so.
Best bet is to have the bottom ball joint & track rod ends (both sides, to be sure) checked, but especially the one you clonked of course. Shouldn't cost much to replace them.