thumping under driverside floor

[Rodney Leary]

I have a thump I can feel through the floor boards. It speeds up when i accelerate. Seems to be worse when turning or in curves, sometimes not noticeable. My first thought is it's related to the body mount bushings that need replaced (I have the center 8 deteriorated and have been waiting for warm weather to fix).



Does that sound like a symptom of the bushing issue? or maybe a ball joint issue?

 

[Ray McIntireJr]

Does the front end shimmy a little too. Sometimes the belts in the tires slip and can cause sounds like that but I beleive that the shimmying usually accompanies that.

 

[Rodney Leary]

Not much shimmying, but I get some good vibration up around 50-60 mph, then it evens out higher than that. The tires look visibly good everywhere. I have no idea when it last had a rotation, balance, or alignment (im a new ST owner for a month or so now). Should I maybe start with tire maintenance first?

 

[Bob McDonald]

Another thought is the drive shaft. Either something caught and wrapped around it, or maybe a u-joint bearing.

 

[Doug Stewart]

I would agree with a drive shaft issue they usually occur at that speed and also can be felt in the seat of the pants. Do you still feel it if you shift into neutral?

 

[EddieS'04]

The first few yrs tracs had steel drive shafts. Some of those cause vibe problems. The fix was ford went to aluminum drive shafts.

 

[Mrlunchbox]

I was just going to ask that very same question about the drive shaft. Had mine up on the lift the other day and I noticed it was an aluminum shaft. I just couldn't remember which one you guys said was bad, the steel or aluminum. Glad I got the right one! :grin:

 

[Rodney Leary]

I will get it out on the highway this weekend and shift to neutral when i can feel the thumps to see if it stops. Thanks for the advice.

 

[David Ponder]

Missed Bambi, but not his rabbit friend??? Sorry, I had to...



I would agree with the driveshaft, EXCEPT, it shouldn't make a difference in curves if it was the driveshaft. Is you ST a 4WD model? If so, I might suspect a Hub bearing. Just my .02

 

[Rodney Leary]

2wd.



thumping continued when vehicle was moving by in neutral. might be tire related after all? I will get it to my local guy soon so he can lift it and take a look.



thanks all.

 

[Bob McDonald]

Don't forget. The drive shaft is still turning while coasting in neutral.

 

[Rodney Leary]

Thanks again.