Picked up my new toy yesterday, everything was good on the test drive. When i got it up to speed on the motorway it started voilent shaking & wobbling either coasting or on the power. If i hit the brakes they shuddered so violently is was frightening, i pulled over, set off & it seemed ok, it felt like wheels & discs were bent so bad the discs hit the brand new brake pads, in fact the discs look new, too. At low speeds it seems fine & even later in the journey it seemed fine, then hit the brakes it unsettled the whole car for a good while, any ideas?

 

It sounds to me as if your front wheels need balancing, or are bent, or both. I work at a Big O Tires, and that's just my .02 cents

 

here is what to look for

1. are your lug nut completely tightened on all four wheels

2. there is a wheel that is out of balance (happens when you reach a certain speed like highway speeds)

3. is the car shaking under acceleration ( like the vibration is coming from the motor) you may have a misfire somewhere (spark plugs, coil packs , ecm electronic control module located on the airbox)

4. is the car shaking while coasting at a high speed? (tire out of balance)

5. does the car shake under high speed braking or low speed braking (you need to resurface your rotors) if you drive an allroad just get new ones (but if you want to be cheap just resurface)

 

My wife's 2002 2.7L Allroad had a pretty bad shake between 50 and 80MPH. Turned out that the only fix was to replace all the control arms (around 100K miles at the time)...balance the tires (replace them if they are near worn)...and an alignment. After that it drove like it was brand new. If it shakes more under braking I would be looking at the rotors too, but if it while it is driving down the road look at the last time the control arms were done (all 8...upper and lower)

I felt that if it slightly turned off course at those speeds the steering wheel would stop shaking, indicating that if the control arm bushings were under load the shake would reduce. Lots of people chase their tails on these cars for the shake

Good luck

 

Ball joints/control arms...