Quote Originally Posted by rotaryenginepete View Post
Jimmiee, I was wondering this listing http://www.gmtruckhq.com/?q=node/93 is out of a transmission manual. my problem best fits # 2 and 3. so this is why i think it may be mecahnical because programming it back to stock settings didn't fix the problem. but it does say TPS as the first thing to change..maybe i got water/mud all up in mine offroading lol
Like I mentioned earlier watching the scanner when the shift is commanded will tell you if you have a mechanical problem or a command problem. This is how a professional would diagnose it. Without a scanner you will have to do it the online way which is to throw parts at it until you either go broke or you stumble upon the right part. Not trying to to be a smart ass, just telling you the easy way to fix your truck.

Also while we're on the subject if you got any water at all into your transmission your transmission should be rebuilt. Water will sooner or later delaminate the friction material from the clutch plates inside your transmission. Changing the oil will never reverse the water damage.