vibration

[i_love_my_stang]

im trying to figure this out, my car vibrates really bad at about 100-140km/hr dont know cuz my speedo doesnt work, now i cant remember what mods ive done since i've driven my car like maybe 10 times in the last 2 years, i installed 4.10s about 2 years ago and drove it and im there wasnt any vibration, now i cant remember if it vibrated before i put my new springs in, i removed both lower control arms at the same time so i had to line everything up again which was a pain in the ass, just wasnt thinking lol, and i've also put new tires and rims on so maybe it wasnt balanced properly, i just tried rotating my driveshaft 90* and it seems like the vibration wasnt as bad does that make sense? any idea of what i can check im gonna pull the wheels and get them balanced and checked this week too

 

[ryclef331]

What exactly did you do with the control arms? Are they adjustables and did you adjust them? Tire balancing would be most people's first guess but you could have a pinion angle issue due to messing with the control arms.

 

[i_love_my_stang]

stock control arms just removed both lower bolts at the same time and the dif dropped, so then i lined the bolts up again with the new springs and bolted it all together