i just recently installed new upper and lower rear control arms. when i took the springs out, the bottom rubber spring isolators just fell apart, uppers are fine. so, when i got done with the install i put the upper rubbers back in but not the lowers. i haven't really driven the car too much. i have now noticed a creaking/clunking sound when i back up or pull forward. do you think it's from not having the lower rubber spring isolators? i guess i could buy some and put them in, if that stops the noise, i know what the problem was.