Speedometer not working, HELP!

I've got a 2003 Silverado extended cab. So I noticed the speedometer needle acting a little bit sticky now and then. The other morning I got in the truck and the speedometer didn't work at all! Each time I stopped and took off, it started to come up a little bit more. Finally after driving for about a half hour and stopping and taking off about four times it started to work "correctly" if you want to call it that. It has been abnormally cold here in the mornings and maybe it starts to work after it "warms up"? My warranty has already expired and I'd like to fix it myself if possible.

Any help will be greatly appreciated!

Thanks

Dave

Alright, so I went by my local stealership and explained the speedo. problem. Guy at the counter tells my he just bought a brand new 2004 and his speedo stopped working two days after he bought it! He then tells me the problem is inside the cluster and the whole cluster must be replaced. Of course they have to remove my cluster and read a number off of it before they can order a new one which will cost between, get this, $300 to $800 IF they can even get one! I ordered a brand new Silverado SS cluster online for $248 from another dealer. Now if I can just get my clunking steering shaft replaced......