I'm back I have not been on since 04. Bummer
My problem is the speedometer or speed sensor. The speedometer started acting up earlier this summer and progressively gotten worse. It started out by slowly loosing speed till it read 0. Turn the truck off let set about 60 seconds and it was fine now last week it started going the other way now you can be doing 10mph and the speedo reads 120 mph. Same thing turn it off let it set and it fine for a while. One thing I have noticed is it seems to start to get flaky after a hard left turn. Any suggestions would be nice.

Grizz

I wish I could help, but as you can see by my avitar I am having the same problem... When I turn the truck on and off it will drop about 5 mph. Some days it is just fine, but most of the time it is way off... starting to think that the cluster is just taking a dive...

Moved to Interior...

Could be the sensor, word is that they are cheap and easy to replace.
Could be a dirty cluster. One member cleaned his and now it works fine.
Mine needed to be rebuilt. Cluster repair (http://dieselplace.com/forum/showthread.php?t=97155)

this was happening to mine and ended up haveing to replace the cluster only cost me $50 because of my warrenty from my bank but it was like almost $400 for them to get a new one and make sure you give them back the old one it is like a $1000 core charge at the dealership

Mine did something similar also. There was an earlier thread, but not sure where it was. My understanding is the speedo loses it zero reset. I had to have the speedo replaced, and it wasn't cheap.