We have had this vibration on our 06 4.0 v6 manual trans mustang. To me its acting like a u-joint..

There is a vibration around 45mph and again at 80mph (give or take a few mph).. Worse under load... It is speed dependent, not gear or rpm.

This evening I got under there and went to check the u-joints. There is slop in the front u-joint. The rear u-joint is tight.

There are no external clips on those u-joints so I'm assuming they are staked in. I've been searching around and haven't found any info on changing the u-joint. I've only seen info on swapping out to a nice aluminum shaft which is more than we really want to spend on a car that is a Daily driver.

Is it possible to change out the joints? If they are staked in, can they be converted to a clip style? If not, anyone know where to find a new take off shaft? I found one in a junkyard (in state but still 200 miles away).. I looked at newtakeoff already and v6stuff and neither has OEM v6 shafts.

I'd appreciate any info.. Its bad enough if I was driving the car but Yolanda uses it to get to work and thats 80+ miles per day.. (The car has 140k or so miles on it now).

~Mark


EDIT: I almost forgot.. Here is the vid I took of the slop in the shaft.. kinda hard to see but you can hear it..
http://www.youtube.com/watch?v=8j8aNPamCQw

 

With that many miles it could be.

When u-joint bearing is bad you will typically hear it 'ringing the bell' as the old saying goes. Usually backing up or taking off slowly and it will make a sound like a bell from the hollow tube as the bearing crunches a bit under strain. That has always been my guide on several vehicles.

How long since the tires were balanced? That would be easier to check out first.

Also, it could be you may have dented it to throw it off balance. A drive line shop can straighten or add counter weights. I ran over a curb once in my coffee truck and dinged it pretty good. The drive line shop fixed it perfect for not much. If it is the drive line, it would be good to fix it quick so the vibration doesn't lead to trans problems.

 

I just put 2 new tires on it and even swapped front to rear tires with no change in the vibration..

Its possible its dented since we live on a dirt road and I know it gets pelted with rocks every day but of course I didn't see anything obviously dented.

The "slop" I felt and heard was only felt/heard on the front u-joint. The rear one felt tight.

~Mark

 

I had a local drive shaft shop make us a new shaft which uses the standard u-joints (I forgot to bring the paperwork with me to work). They They were 1310 series IIRC.

Total cost, out the door (including new tube) was $350.

It took care of the j-joint vibration but we still have 2 more left to figure out.. on at 73mph and another at just over 95mph that goes away just over 100mph. Those are very speed dependent (not rpm or gear) and its very consistent.

~Mark