Just got bilsteins about 4 months ago and within a month, the pass side rear was leaking oil. i sent it back for a replacement but while it was away i bought a cheap pep boys shock and by the time i put the new bilstein back on (about 2 months later) the cheap shock was leaking. I know for $13 i cant expect much, but two months? and a bilstein within a month? anything that can cause a shock to go bad like that?