I'm going to tackle mine this weekend. U-joints first, since it's minimal cost and the unit has 99k on it. I figure nothing to lose there.

Interesting though, mine is a 2000 and already has the shaft with the CV joint in it. It does have a 4" Procomp lift that was suposedlly installed at around 83k but the driveshaft looks orginal and the previous owner never mentioned anything about adding the CV joint. There's no evidence the driveshaft has ever been touched either.

I'll keep you posted on my progress...you do the same?

 

I will for sure!

 

I have the same vibration. It is intermittent however. I am going to take it in since I am still under factory warranty for another 3 months and 10000 miles and have them do a look over on the U-Joints, CV Joints and torque converter.

 

Update:

Before I bought the u-joints I thought I'd at least jack it up and see if I could find one that was noticably loose. What I found was the CV joint has some wiggle that doesn't look like its coming from the u-joints. I've never had one apart and admittedly don't completely understand how they work, but the looseness seems to be coming from the connection throught the center of the joint. I don't think new u-joints would fix this. I think its definetly enough play to cause a vibration. Also, I noticed the slip yoke has some play too, but its more radial, like clearance between the spline teeth rather than axial clearance that might cause a vibration.

The other interesting point is I've noticed from several sources that the Excursions may not have all come with the CV joint? There's still a sticker on my shaft and it identifies the assembly as a Ford Service part, not the original piece. I wonder why it was replaced the first time?

The thought has crossed my mind just to replace the whole shaft.

 

Problem confirmed. I took the shaft out of the truck and in addition to the slop in the center of the joint it felt really rough. Just for kicks, I locked the front end in and took it out for a drive. All they way up to 65 and it was smooth as silk.

After some research I found out that a CV joint not only has the two universals but also a ball socket joint connecting the flange yoke to the weld yoke on the tube. This can in fact wear out too. Mine is most definetly shot! U-joints are ok. What I've also found is that the repair parts for the ball socket aren't easy to get. Seems that sometime in the last few years the folks at Spicer made a deal with the devil (those of us in the automotive OE supply industry know him as Ford Motor Company) and the Spicer parts for our beloved X's are now nearly impossible to get in the aftermarket. You just about have to go through Ford service and they only want to sell complete assemblies not components.

Advance auto has remaned shafts for around $350 but I'd still end up with a non-servicable shaft that maybe a touch short for a lifted rig. So...I'm going with a brand new shaft from High Angle Driveline. I spent a considerable amount of time on the phone with Jesse there and am pleased to say he's certainly a stand up guy. He was super helpful and really knows his stuff. He definetly knows Ford trucks and the idiosyncracies of the Excursion.

I'm willing to pay the $$ to get the piece of mind that I believe is going to come with the quality of his product.

More later...

 

I am looking at the same thing how much was the new drive shaft if you dont mind. I would rather pay now than 300 miles from home with teh toy hauler attached...

 

$469 complete. He charges a $69 core charge unless you hand over your shaft since the flanges are so hard to get, then shipping.

 

Thats not too bad for a new shaft that will fit. I lifted mine 6 inches and tow really heavy. I am starting to see issues so its time for a new one i will call him on Monday.

Thanks

 

Well...

Installed the new rear shaft a couple days ago and the problem didn't completely go away. Its definetly better, but still hear and feel a low rumble starting at about 58mph that starts to fade around 70mph.

Jesse at High Angle Driveline mentioned the X's are notorious for having pinion flange pilot's out of round. I tried to check mine but my indicator wasn't quite long enough so it was tough to measure. It seemed like about .004". I think Jesse said .002 was max but I think I'll call him and talk it over again.

I HATE vibrations

 

I took mine to a local drive line shop. They put in a new tube and made it longer..rebalnced it. Seems to be working fine now...

They said they serviced the slip yolk but I am not so sure,.,.,.