cooter26

Check the 2nd link i posted above.

2000sdime

wonderin if maybe its the neutral saftey switch (black thing with 2plugs on side of tranny)

2000sdime

ok so i went to a dealer and they told me it may be the ignition switch causein my problem which makes sense seein how sometime when i start it up it acts fine then if i shut it off and start it back up it will go back to crap so im gonna try changin that to see if it helps only bad thing is the part costs 130bux ugh so i hope it works

silverado13

well i think there is truth in everything everyone has said so far, as far as the guages, ive never had that problem.....ive replaced my transmission twice now and am about to start on my 3rd, this last transmission that went on me was from the junk yard and was never 100%, it was burning clutches and what not, now as far as the starting off in 3rd gear, that was the last symptom before my transmission went on me, so i suggest stop driving it now before the transmission goes completely like mine.....about a month or two ago was when i first experienced this problem with my truck, at about 3-5 mph the transmission shifts right into 3rd just as you are describing, well about 15-20 miles later, the problem went away and the transmission went back to normal, about a week and a half ago is when my transmission went on me, well this weird shift just came back so i assumed that it would go away. i was trying to get on the highway and i think i hit it a little to hard, well the shifting into 3rd went away but then my transmission would not shift above 2nd gear no matter what i did, ive had a few theories about what went wrong, the most probable is that one of my valves in the valve body was getting stuck and would not open/close (which ever its supposed to) well i believe that when i was getting onto the highway, i broke that valve, that would stop it from shifting i believe, i think there could be some truth in maxxman04's suggestion, although it doesnt have a detent cable, there could be some sort of communication between the throttle position switch and the transmisssion because directly before this problem started, i was messing with my throttle body and i removed it so something could just be off with that but also could be a valve issue, i want to learn the interiors of a transmission so im going to try to rebuild this one instead of just replacing it, i plan on doing that soon, if i find any interesting problems inside the transmission ill let you guys know

silverado13

ok so i have an update for you guys. yesterday i was driving around and i saw a tranny shop that claims low prices so i decided to stop in and just get a price on having my tranny rebuilt, the owner quoted me if i bring my tranny in to him he would only want $600 for a complete rebuild compaired to the previous lower price of $1100, so it sounded good and i told the guy i was considering rebuilding it myself, he says its not very difficult and the average person can do it, well anyways i told him ever side effect that the transmission had like seeming to take off in 3rd and then now not wanting to shift out of second, and aparently my theory about the valve body having a problem was completely wrong hahaha, he said it is a relatively common problem and there are 2 servos that plug into the valve body, and that they most likely are what went bad, while i was talkin to him he was actually rebuilding a 700r4 which is a very similar tranny, and he showed me how to remove them and replace them, they are only like $15 a piece and can be replaced while the tranny is in the vehicle, you get to them through the pan, i have a lot going on this week but am going to try this weekend and see if it is the problem
my transmission has many other problems and needs a rebuild regardless of if this gets it shifting again, so im going to keep it in storage until i have it rebuilt anyways but im curious if this is the problem you have as well so im going to do it and get back to you guys about it, if it is and you are still experiencing the problems then i can give you step-by-step instructions on how to replace it