Transmission lost drive and overdrive

SOURCE: transmission wont get into overdrive or reverse.

sounds like a 700r4 tranny thats usually what happens when they decide to quit you loose overdrive and reverse. About 900 to 1000$ to rebuild.

SOURCE: Transmission fluid flushing

In normal situations people do not flush their trannys. Your would normally just lower the pand and change the filter and replace the fluid that came out. If you are not having a problem with your tranny this is what I would suggest. As the fluid gets older the tranny gets "used to" the old oil that is in there. When you add new fluids the new fluid contains detergents that clean the internal parts as they circulate. Unless this is the first time you've been to the recommended mileage for changing the fluid (I.E. 30,000 miles) you could flush it. If you do not know the history of changes, or if you are at, lets say 100,000 miles I wouldn't recommend flushing it. When the new detergents clean out the parts they remove gunk that is actually helping the transmission. Don't get me wrong, you don't want a whole lot of gunk, but you also don't want to remove gunk that for example is holding a pin in place, so the pin falls out (just an example) I hope this wasn't too hard to understand, and I hope I answered your question.

SOURCE: 99 chevy lumina 94k mi transmission stopped working. Fluid good.

check fluid level, make sure proper fluid is in transmission otherwise take to trans shop to diagnse if level and type is correct(check at idle normal operating temp)

SOURCE: My chevy s10 slips going into over drive. I was

Yes you can put transx in the transmission and it helps with shifting and slipping or lucas trans but i would say it may help a bit but there is a problem with the trans and only going to get worse

SOURCE: 96 chevy blazer 3rd gear and overdrive slipping

i got a 1996 chev. blazer s-s10 4.3 engine 4x4.problem i got is i got 1st 2nd & overdrive & reverse but no 3rd gear what should i do