I just bought my '06 Supercab 5.4 with 40K miles last week. It's my first 150 so I don't know if this is "normal". I've noticed that when in Park, Neutral, or stopped in Drive, there's a significant vibration. I wouldn't call it a "shudder", but its bad enough make big waves in my coffee. When I start moving, it's smooth as glass until I come to a stop again and the vibration returns. No shift problems at all.

I also noted today when I backed out of a parking spot, it gave a serious "shudder" until I hit the brake.

I don't know if this is tranny or engine related, or just a typical Ford 5.4 engine. (I tried searching the forum for similar issues, but came up with way to many threads on "vibrations".)

Could this possibly be improved with a tranny flush?

 

A tranny flush isn't going to help. The problem is in the engine.

 

Thanks. Can you elaborate on what you think might be causing the problem?

 

I was told that the engine mounts are to blame, not that they are defective, just that the vibration transfers threw them. I believe there was a TSB on these affecting the 04 & 05s. After a while you get used to it. On mine, if I just idle in drive I feel it, tap the gas and its gone.

 

Ah. In other words, it's just the nature of the beast. Thanks!