mine jumped around pretty bad when i first got the car but since ive been driving it it only does it under 30mph, id say take the speedo cable out and lube the **** outa it
mine jumped around pretty bad when i first got the car but since ive been driving it it only does it under 30mph, id say take the speedo cable out and lube the **** outa itthe speedo to jump around when your are driving?