why when i speed up to about 70+ i experience waayyy to much vibration, its like i dont even wanna take it over 80 cuz its pretty bad. any symptoms of something i should check? something i can do to prevent this or a mod i can go through?
*sorry i forgot to mention, this is drive shaft related*

 

did it start happening or has it always done it? a wheel weight coming off can cause vibration as well.

 

i'm in the same boat my pass. seat will shake something bad like beat me to death at 55mph+ new tires and al driveshaft so not really sure on what it could be

 

There are a lot of good solutions and things to try here: I can't stop the vibration

 

I had/have the same thing since my 9" swap. I would get an angle finder and check the pinion angle. I am getting an adjustable torque arm some day, but did a ******* job to get the pinion angle closer. Took the vibrations from being scary at 60 to scary at 90. I would check that and also rear U-joint. That pinion angle being off is not good for them.

 

well guys i took the car to the hobby center yesterday and this is what i found when i observed the whole rear, first off i have aftermarket LCA's and pan bar, and just recently did a rear end swap. so the right LCA had a bolt through the Relocation Bracket and another connected forward of it to the frame. well for some reason there was a smaller BOLT than all the others going through this one making it VERY loose i could grab the bolt head with my fingers and turn the whole thing, and the nut would turn with it. so i took a bigger one (the one that's supposed to go in) and put that one in instead. much bigger bolt with a new washer and tightened that mother down with all my strength. BIG DIFFERENCE that **** made. weird how something little can do that? no my vibrations arent that bad at all, just the regular little vibration at like 90 95 but thats from stock DS. so i can honestly say, problem solved

and for your info guys i appreciate it.