vibration help

[jerzram]

i have a 99 explorer sport with a automatic trans. my problem is i have a vibration when i push the gas pedel all the way to the floor and it gets worse when the passing gear kicks in. normal driving is fine just when gas pedel is pushed all the to the floor.

 

[Rick]

I would start with checking the u-joints in the driveshaft. Can't recommend much more than that without more info.