I have a 2004 F-150 Super Crew Lariat which I bought new and I just turned 300,000 miles. The truck has been very well maintained and is in great shape. It is hands-down the best vehicle I have ever owned and I have owned plenty.

I drive mostly highway miles and lately I have notice a slight roughness or vibration when driving straight or turning right. If I turn left of center it drives as smooth as the day I bought it. The dealer can't figure it out, or they don't have the experienced personnel and/or they don't care to figure it out because of the high miles. They checked the power steering pump, which checked out fine and that was as far as it went. Any ideas???

Thanks For Your Input and Help.

 

I would be looking at a wheel bearing (if it's 2 wheel drive) and an IWE (if it's 4x4).

My 04 F150 4x4 did that exact same rumble / vibration thing and it was an IWE. Replaced the bad one then I could hear a faint rumble from the oposite side (which I couldn't hear from the noise of really bad one) replaced the other while I was at it and been smooth as silk and quiet ever since.

Could be something as simple as a loose wheel lug nut doing it.

 

Thanks for the advice. It is a 4X4, I will let the dealer know and hope that is it.

 

Good thing to try, is when it rumbles, slow down and engage the 4WD. If the rumble goes away it definitely shows its an IWE. At least, that's how I found out what my rumbling was.