Noticed my 2002 F150 had a very slight vibration in the seat / steering wheel when cruseing down the highway at 60 MPH.. Very slight, but was not there 2 weeks ago.. It seem to get a little worst as the 2 weeks progressed. Got all 4 tires balanced and rotated... no help...Took both rear wheels off-- no problems with tires -- checked bearing clearance-- pushed and twisted on driveshaft yolk to check pinion bearing... nothing found......... last resort was drop back end of driveshaft and check U-joint.. It was tight and dry. Put drive shaft in 12 ton press and pushed out the u-joint bearings. Very dry and joint pins were starting to spall....... I mention this because I had checked " clearance" and "slop" and had "no noise" before removal... Truck has 139K miles on original u-joints .......... Something to keep in mind. Eventually it would have worn to the point that it was obvious, but in the first stages of failure, you just get small symptoms.

 

The rear ujoint on my 2001 went **** up at 150000 miles with increasing seat of the pants vibration similar to yours. When I pressed the joints apart, I stretched the yoke holes even though I was careful not to, so the new cups would easily push in with finger pressure. Ended up just getting a local drive shaft shop to build me a new shaft without the front rubber dampener type front yoke. Works fine without it.

 

So Steve, did you just repack the bearings and reinstall, or put in new?
Both ends?

 

I started at 10 am and had an appointment at 1 PM. I found the problem at 11 am. ran to Auto Zone and bought two generic u-joints with grease zerks for $15. each. Rear joint had failed... spall marks on two of the four bearing shafts. Took 30 minutes to get it apart with 12 ton press and clean. Got installed the new joint and ran out of time to do the front. It feels OK... will do it next warm weekend. Got shaft back in at 12:30.

 

Good job Steve.
Thanks for the details.

 

Thank you. Is this something that I should be looking at as preventive maintenance? Rather pull the driveshaft and have a shop throw on some new U joints than be stranded.

 

Yes, I if was in the 120-150K mile range and had the originals, I think I would plan ahead and get them changed... I remember 30 years ago you could do this with a 2 pound hammer and a punch.... This one took 12 TONS to get two of the 4 caps to move... and I had to press them back and forth 3-4 times until it was loose enough to get one cap off to pull the joint out of the 2nd cap. ... After cleaning the bores and getting new u-joints, it took about 500 pounds force to push them back together................... of course, being 14 years old might have something to do with that !!

 

Not sure about every year, but mine only went back on ONE way. No need to clock it when one spline is completely different from the rest.