2 wheel & 4 wheel alignment?

I (for the most part) know the difference between a 2 wheel and 4 wheel alignment (it's pretty self explanatory, and I did a little research), but how do I know which one I need? I drive an '08 Focus, front wheel drive. In my opinion, I should get a 4 wheel alignment. I know that I need an alignment for sure, and I think that my needing that is what cause the heavy cupping in the tires that I replaced last week (in reference to my last question asked). I am afraid that the cupping is result of poor shocks/struts, but I am sort of "assuming" it's from the alignment because I know for a fact that I need a re-alignment. How could I tell on my own if I need new shocks/struts? I read something online about doing a test by pushing down the hood, then the trunk to see how quickly it springs back up --- but I don't know what's "quick" and what's not.


Any and all information would be helpful. I am a poor college student...to say the least - hoping for a cheap fix, LOL.





I appreciate it!|||True cupping is generally caused by two things - either bad shocks or cheap, not-so-well made tires. Poor tires tend to wear quickly and unevenly - not a very good bargain after all is said and done!





If its a feathering that doesn't cause road noise, that is more likely either improperly inflated tires or a misalignment.





Generally your shocks/struts shouldn't wear after only 2 years of driving, but generally the "shade tree" test is to push down on the corner of the car, and quickly let go. the car should only cycle about 2 times, with the action dampening very quickly. Looking into the wheel well (turning the wheel your inspecting outward helps), you should see your strut/shock boot in good shape, with no tearing evident, and no indication that fluid has leaked from the shock. There also shouldn't be any major groaning noises or such when you do the "push" test. Slight noise is normal.





The best thing to do is to get the alignment done, and let the mechanic inspect the struts (which is generally what they do as part of the procedure).





Good luck!|||when you push on it the car should only bounce one time and maybe a little another if it doesnt stop bouncing after about one or two times it is time for new shocks.....im assuming by cupping you mean that the tire is worn more in the middle than it is on the sides...that simply means the tires were over inflated....most all cars only need a front 2 wheel alignment since that is what steers you most of the time the back wheels are set on and axle or placed on a rotor that wont adjust ....sometimes rarely you will need an alignment on some cars but mostly if it is 4 wheel steering or it has a tuned racing suspension....you can roughly check your tires for alignment issues by measuring with a tape measure ....measure how far apart they are on the front and then how far apart they are in the back and coinsider the difference ....then do the same thing with top and bottom .....if they are the same you probably dont have a problem .....this way you can make absolutely sure b/c some shops will rip you off and say they did an alignment when in reality there was nothing needed to be done|||The test you refer to is to jounce the car on the front or rear bumpers at each corner . you do this by bouncing the car hard two or three times and it should oscillate or bounce no more than once or twice after you quite pushing the bumper down and up


Worn parts can cause cupping but it is usually associated with shocks


Now a bit of bad news when you replace the struts you should get the alignment done. Because they are a part of the steering components along with the suspension components as in upper control arm and upper steering pivot point|||Why do you drive a new car if you are so poor? Maybe you should sell it and buy a vehicle that you can better afford. Take it in and get it aligned, they will take care of the guesswork.