Dove in today and greased the slip yoke today to try to see if it stops the 'bump' I felt every time I stopped or started moving.

Safety first...my driveway has a slight downward tilt so I hit the e-brake, chocked all 4 tires then put the truck in neutral (just in case I needed to wiggle the driveshaft a bit to get it out).

Did a front to rear check of the shock bolts, front sway bar, etc. Found the front sway bar to connector bushings are wasted (some say that could be the cause). Made a mental note to order some and decided to do the slip yoke lube since I had the tools out and ready.

Note: Some other posts noted what appeared to be a 'double-wide' tooth on the splines that prevent you from putting in the rear drive shaft back into the front in anything else than one position. Turns out there IS what appears to be a double-wide tooth on the female end, but it only goes back about a quarter inch then the 'missing' tooth comes back. I checked the male end and all teeth are equal spacing and length from what I could see, so to me that means it is important to scribe the driveshaft position at the rear axle-to-driveshaft and at both ends of the slip yoke itself to make sure you don't throw anything out of balance.

I used a punch as an awl and marked both before I removed any bolts.

I broke loose all 4 flange bolts from the rear drive shaft to axle and removed three. Took an old 1" nylon web strap I used for securing stuff to my CERT pack and wrapped it around the rear drive shaft just forward of the universal up over some kind of vibration dampner:


I then pried a bit against the universal and rear drive shaft flange with a sturdy screwdriver and the shaft compressed and the webbing took up the weight:


Removed both of the bands on the rubber boot since I wasn't sure what end was the male and female. Turns out the front 'short' end of the rear driveshaft is the 'female' and the longer end is the 'male'.

Once I pulled them apart I found virtually NO grease:


I think the shaft was sticking on the blue goo that Ford put on, and that the 'thump' is the driveshaft lengthening and shortening. I had some BelRay waterproof grease I used to use on my motorcycle axles and hubs. It may only work short term but since this was a 'diagnosis' type of job I fibgured it's no big deal if I have to come back and re-do it.

I slopped a bunch into the female end of the axle and then put a bunch around the splines on the male end.

Slipping the axle back together proved to be a real PITA. The first inch went in pretty easy, then got REAL tough. My guess is there was some old grease in the teeth of the female end and the new grease was making the fit tighter than usual.

I first started in with a rubber mallet and that worked for about another half inch to an inch, then stopped being effective (had I put the truck up on a lift I could have probably finished it off with the mallet, but being on the ground I had no room to swing it). I had a tool for carpentry that you use to pry up boards during remodels that had a nice curve like a nail puller. The tool has it's rubber protectors on it, so I put that against the rear axle flange and pried back and the axle slipped back smooth as silk.

NOW...the driveshaft is a bit too short for the driveshaft to rear axle bolts to bite. Back to the carpentry tools to get two C clamps. One aligned to one set of bolt holes, the other aligned to the opposite set, then just crank them down slow until you get all 4 bolts to bite at least 2 turns.

Crank them down to 82ft/lbs and remove the webbing strap. Be sure to resecure the rubber boot (I used zip ties as a temporary fix until I could run to the hardware store to get some C clamps).

Just like that it was done! Double-checked my torque on the bolts and off to road test. NO SOUND AT ALL...this WAS the culprit of the 'thump'. Still going to order the new sway bar bushings. I have heard issues on pressing them into the connector bars...anyone think a vice would work? Has anyone ordered just the bushings or the entire new set of connectors - if so, reviews on prices and performance and some vendor names?

MANY thanks to those that posted their "how-to's" - it made this a 30 minute job!

 

Great, that was an easy one...

 

Vice will not get it. Took mine in to a shop with an 18 ton arbor press and it took all she had! Or some folks torch them out. For me they charged $15 to remove them, saving me the time and frustration, considered heck of a deal.
Energy suspension seems to be the most recommended. That's what I have and installed easily. After 5000 miles in them still look good.

 

Those driveshaft splines were made too tight at the factory but that grease will probably last as long as you have that truck. Mine did it when I bought it which is why I got a good deal but it went away a week later.

 

See, now that suprises me. My rear sway bar bushing on my 97 Expedition somehow came out of the arm and I was able to get it back in using a vice and some WD40. It never came back out either...