I have a vibration between 35 and 50 mph. and sometimes by 65-70.
you can see my bed shaken and my headache rack,
my hole dash shakes.
Have new transmission and just spent 3500 in my frond end incl, new tires and hubs, brakes , steering box
any ideas??
2001 dually

 

What engine? Does it get MUCH worse right about 45 mph? How are the tires??

Welcome to DF!

 

diesel new , front tires
vibration stays always the same

 

Did you check the u joints?

 

all new, plus shocks

 

Do you feel it thru the seat, or the steering wheel?

Center support bearing on the rear driveshaft been checked? I might be tempted to rotate/balance the tires, just for giggles.

 

tires done, can feel it thru the seat, steering wheel is not vibration.

 

So it's likely something in the rear part of the driveline.

When did the vibration start? After the tires? Before?

 

Before,after I did all the front end work still vibarates

 

Take it to a good driveline shop, even a semi-truck place, since its dually and diesel. A lot of times those shops are better and quicker diagnosing issues than regular car shops.

Could be a bent wheel, warped rotor (they're huge), bad tire, out of balance tire, warped driveshaft, etc.