I presume you mean the ride is terrible? Most likely the springs are sprung, and you have rear sag, and your fronts may be pretty worn out also.
look at top of this very forum page 1
About rear sag...
if never done you could get them for free... weirder things have happened...
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06 4th gen V8 4WD of course...
08 Honda Ridgeline RT
05 Scion xB-the toaster-daily driver
my Yota Fanatic photos are on Facebook- here is link:
http://www.facebook.com/album.php?ai...5&l=5795132731