I'm hoping you guys can help me out here, I have a 2004 f150 crew. 5.4l. I was driving home from the lake this past weekend towing the boat, I felt like I had a flat tire so I pulled over and every tire is fine. Was going about 55mph. Today after a day of fishing, on the highway doing 70ish, I felt the same thing. No flats. It happened for about a half mile each time then went away for the remaining hour ride home. Any ideas? I'm going to check the lug nuts on the truck and trailer tomorrow, but if that's not the case, I'm lost.

Thank you

 

If the air was good on both truck and trailer tires am guessing may b the brakes are binding on the trailer wheels when you apply brakes. Is that a feel like you drove with handbrake on..??

 

The best way I can describe it is it felt and sounded like I had a flat somewhere. It bounced so much that my windshield wipers were bouncing about an inch up and down. I wasn't hitting the brakes when it happened and I tried all different speeds and it didn't change that feeling.

 

Might be bad u-joints. Mine are going and do the same thing every now and then

 

Okay I'll check out the u joints. I'm just trying to get an idea of the possibilities to start checking. I have a long ride to this weekends tournament and I don't want to have issues towing on the way up or back.

 

When it starts do feel in the seat or does try to rip the steering wheel out of your hand??

 

You can feel it in the seat and everywhere else. The entire truck shakes like crazy. But the steering is straight and acts like there is nothing wrong. Steering, brakes and acceleration all act normal. Just bounces,shakes and vibrates like crazy then goes away after a half mile ish both times. Haven't been able to re create the problem today.

 

long shot=motor mounts?

 

That makes me suspect the u-joints even more. You can try pulling over while it does it and backing up a few feet. Seems to make it go away on mine at least.

 

Are you running wide tires? If so maybe a flat spot is forming from being parked for a while and tires round themselves back out after driving a while.