I noticed a horrendous noise in 4x4 when turning left even on slippery ice. A quick look confirmed the front left u-joint is shot. It hasn't worn through the cap yet, but there's plenty of fresh metal showing and it wobbles easily.

I found the Spicer 5006813's nearby and was ready to order them. I read all teh great 'how-to' articles on this site (thanks all who posted, you guys are great! It takes a LOT of work to write those articles up..... It really helps us and is appreciated!) Just for kicks I called a local front end shop I trust and asked for an estimate (Well it is 2 degrees here, and the shop is pretty dang cold..... )
The local shop said they use Precision 464 greasable joints and would do both sides for $440.00

I figured that was low enough to keep me in front of the warm fireplace instead of freezing in the shop......

 

Don't do it, these are Napa joints and I already worn out a set in 35,000 miles.
Stick with the Spicer sealed (non greaseable) and you'll never have to do it again.
FYI I removed both shafts myself and brought them to the local Napa Shop, they pressed old joints out and put my new ones for $ 85. With Napa joints it was $ 145

 

i didn't know Napa would press joints! Thanks for the tip!
I take the truck in tonight. I'm going with the Precision greasables because that's what my mechanic uses. If they don't last I'll try the Spicer. Hopefully if they fail it will be in summer when I have a chance at changing them myself without spending $400 on heating my shop. It's -12F this morning.. Brrrrrrr.