What causes car to shake vibrate hard?

Answer 1

Because it is old.

Answer 2

the shake a rest is most likely a motor mount problem. i have the same problem with the shake after putting new tires on my 18 in. rims. i believe that if you dont have a u-joint problem then those tires are defective. tell the shop to order different tires and try again! good luck

Answer 3

I took my son's car to the shop to place new tires on the vehicle. The car wasn't shaking before and now it is shaking at all times, idle, driving...I think it isn't accelerating  as quickly as well. Help