Vibration on acceleration

[aaron keehn]

The truck vibrates when I get up to 35mph but stops vibrating when I let off the gas. Is it the tranny mount or the u joints on the driveshaft?

 

[Richard L]

More likely the U-Joints. Very typical of U-Joints to make noise and/or vibrate under load and then the problem goes away when you let off the gas and take the load off the U-Joint.



It's always best to just replace both if one goes out. U-Joints are fairly cheap, and only requires about 15 minutes more more labor to replace the other U-Joint, once you get the drive shaft out of the car



...Rich

 

[Gavin Allan]

I would agree with Richard. I have had U-Joints fail, and this is an early symptom. Dealer replaced the entire rear driveshaft of my '10 Limited under warranty because replacement U-Joint did not eliminate all the vibration and rumble. New driveshaft fixed it fine.

 

[Richard L]

Gavin is correct that some early model Gen-1 Sport Trac's had a problem with vibrations at higher speeds(70 mph+, not 35 mph) that was caused by the steel drive shafts. Ford replaced many of those drive shafts under warranty with new aluminum shafts....that seems to have solved the problem.



...Rich

 

[EddieS'04]

My experiance with u-joint vib. At 35 to 45, it has been the front one.

As Rich said only a couple of minutes to replace both. Be sure to put some grease on the front yoke splines.

 

[aaron keehn]

I really appreciate all the help Rich, Eddy and Gavin. I am in afghanistan doing a tour with my MN Army National Guard unit. I have purchased some nice things for a ST that I have waiting for me at home. I love this site and will be posting LOTS of pictures when I get home. I have some fun Projects in mind for the ST. Thanks again!

 

[EddieS'04]

:supercool: stay safe and come home. Thanks for your service.....

 

[Gavin Allan]

We really appreciate your service, Keehn! Please keep safe. :banana: