I have a 2007 E350 with just under 140k miles on it. Just recently when I get on the highway the left front end starts to vibrate around 50 and gets worse as I increase speed. As I am driving after a few minutes the vibration gradually decrease until it is gone entirely. I can then cruise at highway speed without any issue at all. Has anyone encountered somethin like this. Thanks

 

You likely need to replace the entire front suspension. Don't panic as the system is designed to be removed and replaced. It is not a hard job.

With wear at the ball joints and bushings, you will get a shake in the front end when those components are worn. With your mileage, that's likely the issue.

 

Is that a DIY job or strictly professional. I can do a fair amount of work on a car when I know what the issue is but absolutely no diagnostics. Some suspension issue was my first thought also but I can not grasp how it quickly disappears and the ride smooths out.

 

It is a DIY job moderate level. The lower ball joints will need the press out and press in tool and you will need the separation tool for the joints. DO NOT use the old pickle fork ala 1972.