Clunking sound

I could be way off base here...

It is possible that this noise is caused by the swaybar "end links" or "drop links". Many OEM end links have a bit of flex in them which can cause a clunking noise when hard turns are made or when the car passes over road imperfections like you described. It could also be caused by the swaybar shifting in the bushing. If the problem is the end links, you would need new end links or custom-made end links which are solid and have no flex. If the problem is the swaybar shifting in the bushing (probably more likely), you would just need to take off the bushing and regrease it with a heavy duty non-lithium based (waterproof) grease.

AFAIK most aftermarket suspension manufacturers recommend regreasing swaybar bushings every year or so to prevent a noise like this from developing; depending on the positioning of the swaybar collars a certain amount of road grit is collected by the grease and transferred into the bushing as the swaybar shifts. Because of this they eventually dry out and make noise.

Like I said, it's a shot in the dark. But when you said where the noise was coming from I figured it would be worth mentioning the possibility.

 

Are the tyre sizes OE? Probably are since you only hear it coming from one position.

It's not unusual for a 'bottoming out' of a a tyre if you hit a really bad bump.

Check the shocks for any signs of leakage, and also the shock bushings.

From your description, I don't think you have a problem.

As far as the steering wheel being off center, try driving on the ridge of the road (roads are banked to the left and right for water drainage).

If the wheel is still off, if may have been removed at some time and replaced a couple of teeth off on the splined shaft. Or, the front end may need to be realigned with the wheel centered?

 

Skip has suggested a good test for the steering wheel. One inch is (IIRC) two teeth on the spline. Not hard, just a bit fiddly. When you have it right, mark with a marker pen on the housing, shaft and female housing. Toe is set right, right?

 

It depends on how hard the hub is stuck on the steering column's splines.

Try this first:
Put masking tape around the horn button to protect the wheel. Pry the horn button out gently with something smooth like a plastic putty knife. Or slip a loop of fishing line or dental floss around the horn button & pull it out.

Use a ring nut tool to remove the large ring nut holding the hub down on the splined shaft.
This thread illustrates a home-made tool you can use:
http://70.85.40.84/~ferrari/discus/messages/256120/251088.html
or you can buy a FER105 tool from Baum Tools:
http://tools.baumtools.com/index.jsp?index=2&newIndex=1&menu=ferr
for a mere $85 or so + shipping.

If you're using the Baum tool, it's a very snug fit inside the steering column. You must Push the horn wire down into the hole in the hub it's coming up thru. Otherwise the tool will cut the insulation on the wire(been there). Once the hub is off, tie some dental floss on the wire so you can pull it up thru again when reinstalling the steering wheel.

Once the nut is off, grasp a pair of the steering wheel's spokes & give a good yank. If you're luck it'll come off in your hands.

IF HUB DOESN'T COME OFF FAIRLY EASILY:
If it's stuck on, then you'll need to remove the steering whell from the hub so you can use a steering wheel puller to remove it. Remove the 6 allen head screws. The screws are loctited on. Use a hex socket with an hammer drive o impact tool, or a butterfly impact air wrench to break the screws loose. Don't use one of the L shaped allen wrenches. They generally just strip the hex out of the screw.

Once the wheel is off, the 2 holes for the steering wheel puller are exposed. They're metric threads, so make sure that the puller bolts are also metric and easily screw into the hub.

CAUTION: The US bolts that come with some pullers are almost the same size. They'll go in about 3 threads, then start stripping the threads in the soft Al hub. In this case yo'll have to buy metric bolts.