Shaky

Can someone tell me where to look, or does someone has an idea.
My car is vibrating (shaking) a bit when driving. Even a little vibration in the steering wheel. I feel it the most in my front seats. It just began shaking/virbation. It becomes more shaky between 70-80km. Above that it seems to be less vibrating.

have your tires looked at - could be out of balance, broken belts, bad tie rod ends - a number of things

i suspect broken belt in the tire

My 99 Venture had the same thing when I bought it in 04 with 44K miles.

Here are things I had done looking for it:

Replaced front rotors -- took care of it for about 20K miles.
Replaced tie rods (outer)--helped, but did not completely eliminate.
Replaced front struts and rear shocks -- improved ride, but not shaking.
Replaced four tires and new steel wwheels (tirerack) -- did not do it.

Didn't think my front rotors went again, but they did...replaced them gain at 90K, and shaking went away.

All to say that some of the above probably contribute to some of it, but the brake rotors seemed to do the most to take care of it. Also, check the rr drum brakes. If the shoes are not helping in stopping the car, the front rotors warp easier.

The wheels are balanced, so that can't be it.
I thought that i heard a knocking noise today, while driving over a bump in the road. At the same time the floor creaked. Could that be the same problem or some different problem. I will check the rotors tommorow.

I had the knock and the creak, too....changing the tie rod ends took care of the knocking.

Others in the forum had repaired sway bar links for the same symptom.

These are the inexpensive repairs that probably need to be done anyway.

The swaybars don't seem to be defective. The tie rods either.
It just had it's inspection, and no one said anything.
The strange thing is that the vibration/shaking is at his "best" around 70-80km/h in the fifth gear. In the fourth gear the vibration is much less.