Car Shakes/Vibrates on Full Throttle? Help?

[rickymh]

Once and a while, It feels like my rear end is Vibrating/Shakes from left to right when punching it on the freeway from a 40mph roll. The Shaking increases as I go faster. Im scared to go fast now!

The only thing Ive changed in my car before this begun was i got new rear tires. I had Pirelli 265/35/r18, now i have 265/40/r18 Nitto 555.

I had the Pirelli's on with a 1" wheel spacer, that I took off when I put the nitto's. Do you guys think its the tires?

 

[Tom's_03SVT]

driveshaft, tire balance.

 

[sonic_4.6]

Check your lug nuts. :-D

 

[brkntrxn]

Lugs, tires, axle nuts, driveshaft

 

[rickymh]

Im going to check my lugnuts, tire balance.

 

[SVT1012]

I had a 5.0 GT that did the exact same thing. It ended up being the input shaft in the transmission. Ran me about $300 for machine work and labor. Good Luck!

 

[Nightzx]

same thing is happening to me. I was told it was the IRS bushings. I took the wheels off the back and the little rubber bushings on there right now are all ripped apart and look like they're all blown out. Gonna get some urethane or those delrin ones. I was told that would fix my problem. I cant go faster then like 60 or 70 under WOT without my car shaking enough to where it feels like its gonna shake itself apart and flip over in the process.