Lately I have noticed that when I let off the gas i feel a brief vibration. The vibration is usually over in a second or 2 depending on how far off the gas I lift my foot. Vibration feels like it's coming through the floor but I realize that can be deceptive.

Most noticeable when traveling above 40mph and let off. Don 't notice it when accelerating.

351 w/ 4 sp automatic. 261,000 miles. Pretty much stock everything.

I'm thinking I should replace u-joints. I don't think it's the tires, but I could rotate front to back and see if it changes anything. The rear tires are only a month or 2 old.

Any ideas?

Thanks,
Marshall

 

Definitely want to check u-joints and I would check and lube your slip joint as well, while you are messing with all of it.

 

Thought mine was u_joints. Turned out it was pinion bearings into the rear end. Found it when I checked the u_joint and the whole shaft moved up and down going into the rear. . . that was fun

 

Thanks guys. I think I'll start by replacing the front axle u-joints and redoing the bearings/seals while there. The front has been clicking/knocking for a couple months. Then to the drive shaft u-joints/slip joint and will check to see if the pinion feels loose too.

 

It turned out to be the driveshaft. The ball joint of the CV portion was dry as a bone and was disintegrating. Picked up the repair kit from Bronco Graveyard for roughly 120 including shipping.