There are several possibilities ranging from worn out front end parts to unballanced tires/wheels, from bad tires to worn out shock aabsorbers, worn u-joints (especially noticable when applying the gas pedal) to losealug nuts. Is it a rhythmic vibration or a front/rear end only vibration? Does the aft end of the van vibrate with or without a load? Have you "kissed" a curb and caused the wheel(s) on one side to "go out of round" , bend? One or more new tires, while not replacing at least two of the same size front or back? Different tire sizes (is one "taller or smaller"?)
Analyze the problem(s) and be more specific, please.
At times a "soft" front side wall will cause vibrations at certain speeds, while "soft" side walls on the rear wheels cause a swaying rear end at very low coasting speeds and show up, again, at highway speeds giving a skip and jump, like a pogo stick at higher speeds, the rear axle assembly could be misaligned...etc., etc.,...
Observe, analyze and slow down till it is "fixed", please
At or near the same speed as the traffic on the freeway.
It is possible it is one of the speed sensors.
The answer is: speed of traffic
The answer is: speed of traffic
about the same speed as freeway traffic
40
It would be 65 MPH.
In normal Conditions, if the speed limit is 65, it is generally 50. If the speed limit is 55, then the minimum is 40. In Ky the minimum is 45 mph on any parkway or interstate.
That depends where you are driving. In the city, expressways are often limited to 55 mph. In country areas the speed range can be from 55 to 80 depending on where you are driving.
14 hours 6 minutes. This is the total driving time at that speed and excludes stops or delays.
It could be the Torque Converter Lock Up Solenoid... Disconnect that and see what happens.
Yes they should, when you are driving on a freeway they then to be strait and fast and you tend to get bored. However, they can be pieces of shreded tyre on the road or pieces that have fallen off a load or animals (deer, badgers etc) that you may impact. At speed an impact will do allot of damage and may cause you to involve other cars. You need to be vigilent at all times when driving but especially so on a freeway.