Attention: TDR Forum Junkies 
How different are the American axles from the Dana? I recently changed one of my front ujoints (on my '98). The hardest part was loosening the axle nuts. They'd been installed with a 3/4" impact wrench; there was no way I was going to get them loose. So I went to the shop that installed them and asked, "Hey! Can I pay you $20 to bust my nuts loose?"
And, of course, the ujoints I bought were for the light-duty 2500; I had to go out again and buy the correct size. I couldn't find a 6" bolt as Steve SL suggested, so I used the 4" bolt I found, put a short socket on the hex and a larger deep impact socket over the smaller socket, started the engine and used the power steering to press the hub off. Two good thumps holding the pressure for a moment did the trick; the hub nearly fell off. I forgot to use penetrating oil, but the P/S imparted enough force to bust the hub loose anyway.
While the hub was off, I dremeled the mating surfaces clean and applied an amount of anti-sieze to ease the job in the future.
Then it ended up being a matter of using small and large sockets to tap the old ujoint caps loose and using a vice to press the new caps/ujoint in place.
A 1-11/16" socket handled the axle nut nicely. I cheated when I put it back together. I tightened the nut to the requisite 172 ft-lb, then used the floor jack on the breaker bar to continue tightening the nut until I could get the cotter pin in place. (Actually, I could only find a 42mm socket; it was a snug fit, but did the job very nicely. )
It probably took me four hours to change the one ujoint. Twice. A cap fell off and I didn't get all the bearings back in place. So I removed it, tossed it in the trash and installed the second one. (One bearing was in the end and broke in at least several pieces. I decided to trash it rather than try to salvage it. $15 is cheap edjimication. )
So, the things you need to change 2nd-gen front axle ujoints are:
- 1-11/16" or 42/43mm socket with breaker bar and an adapter if needed for the axle nut
- correct ujoints
- 12 pt. socket for the hub bolts
- 6" grade 8 bolt same thread as the hub bolt to 'press' the hub off using the truck's P/S. A 4" bolt with nestled sockets to make up the 2" difference will also work
- grease gun to lube the new ujoint and everything else while you're there
- brake cleaner
- work bench
- bench vice
- 3# mallet
- a variety of medium and large sockets for general pressing
- a nice sunny afternoon; not too warm, not too breezy
- an extra pair of hands to hold stuff
I would expect 3rd-gen axles to be reasonably similar.
Of course, if you have a life and can't find an afternoon to do the job, strongly suggest to the shop that they use the bolt and P/S trick to press the hub off; it'll save a lot of time and effort.
