I just took the winters off my 08 G37S and put the 19s back on. I tightened everything up and when I took it out for a test drive - it shakes like crazy at moderate to highway speeds? Any ideas why it might do this?

 

unbalanced tires, bubbles, alignment, or you didnt tighten the bolts tight enough and your wheel is about to fall off!

 

I just took them off for the winter , I definitely have them TIGHT. Everything was great with the 18" winters and I had no issues with the 19's when they were on before. It just happened when I put them on now. I inflated them to specs and the TPS's are off

 

Did you check the air pressure? They could have deflated some since then.

 

Thanks for the help.
Yeah they are good for air. Does it matter which side they go on? Those tires can be swapped side to side right? I have the fronts and backs on correctly (obviously) but the L/R sides might be different. It is worth switching them around ?

 

You kept them on the rims right? You might have the tread reversed if you put them on different wheels.

 

Yeah - same rims. I just didn't make sure the L and R wheels went back on the same as before. Are these directional tires? I didnt see arrows... Maybe I'll switch them to see if it makes a difference.

 

No, they should be able to be swapped side to side as long as the outside stays on the outside which isnt your problem if you kept them on the stockers.

 

Is the shaking consistent throughout speeds or is it only at higher speeds? This doesnt sound like an alignment to me but rather something wrong with the tires themselves.

 

one of the wheels might not be properly seated on the hub ring. unmount the wheels and try it again.

 

^^^^Ding ding ding!!! Winner winner chicken dinner.

 

lol. what's my prize?

 

darn.....didnt think of that.

 

A chicken dinner. Genius!

 

Actually the tires are directional. You should make sure you have them on correctly.