If you have a bad wheel bearing or u joint check out this thread. It really helped me when i had to replace mine about 5 months ago.

http://www.pavementsucks.com/tech-article-5.html

 

That's a great link. I've already read it and it seems very helpful. Doesn't look like it's all that much work but it may turn out to be.

 

clicking is u-joints. check it by parking on level, in neutral, brake off, no tension on driveline, wheels blocked. try to twist the u-joint - any movement at all, or missing seals is bad.

to check front wheel bearings, grab the top of the tire and shake it in/out with all your might. any movement is bad, although it could be ball joints.

 

still could be u joint. 2wd mine did it slowing down, speeding up etc. if i was moving it was clicking. easy to find out yourself, roll your windows down and drive close by a wall or something that will give a echo, drive in both directions. once you KNOW what side its coming from its easier.

 

if it is non abs its around 100 but with abs your lookin at 2-300

 

I had the same situation in my 97. My u joints were bad on both sides. Not the drive shaft u joints but the wheel u joints. I was able to see they were bad and they made the same noise you are describing. Was not a very hard task to change them out but I think I wasted an axel seal putting the shaft back in so be careful of that. I did not pull the spindle, just pulled the three bolts holding the hub bearing and the whole thing slide right out with a bit of tapping to unseat the hub bearing from the spindle. You will need a BFH the get the old joints out.

 

Okay so a little update. I checked it out today and the hubs seemed very tight. I was kind of shocked as they have a lot of miles on them but so far they are holding up well. Anyway, I then checked out the u joint and it looks completely shot. It seems to be the cause of the noise.

I've taken the axle out of the truck but haven't taken the u joint off yet to change it. I'm going to do that a little later this afternoon. Taking the axle out would have been like a 15 minute job except I had to go to the store twice since I started already. I realized I couldn't find a 12 point 14mm socket. I thought I had one but apparently not or I can't find it. So I had to go get that. Then I went to clean the axle off and realized I was also out of brake cleaner so had to go pick some up. So what should have taken 15 minutes has taken me an hour.

 

Glad to hear you found out what the problem was and fixing it now