Hi, I posted on this before, but my issue is still not resolved because it has been cold, and the blazer has been sitting since my first attempt. I'll give you a run down of what I have done so far.
Shifting was initially fine on this blazer
1. I was told a while ago that the seal between the transfer case and transmission was bad, so fluid is travelling between them. Drained approximately 2 quarts of excess fluid out of the transfer case fill hole.

2. Replaced the transfer case vacuum switch because it was leaking fluid into the lines.

3. drove the blazer approximately 1/2 mile. Not shifting into 3rd gear. went back and checked trans fluid. Low, but not close to empty. refilled, no difference.

4. Took it to a %$# mechanic who sat on it for 5 days and told me I needed a used transmission for $2800. I don't think he even looked at it.

5. took it home, removed pan and replaced A and B shift solenoids. No 3rd gear, but 1-2 shifts really awesome now.

6. called the transmission guy here in town, he can't look at it for about 2 1/2 more weeks because he is going on vacation. He told me to try replacing the 3-2 downshift solenoid in the mean time (any thoughts on this?). I guess it makes sense if the solenoid is stuck in the downshift position that it could never upshift, or doesn't it work that way?

I didn't put a filter in the first time, I figured I probably should do it if I am going to take the pan off AGAIN. But, I see filters for both deep and shallow pans listed, how do I know which one I have?

There was no CEL for this, but the tranny guy says there isn't always one for stuck solenoids. What is everyone's thoughts on this? Shooting in the dark and replacing solenoids MIGHT save me a ton of money if it works out, but right now it is just that. I have yet to get an actual diagnosis on this, and won't until the trannsmisson guy gets back.

Also, he told me about $1700 to rebuild it, and he made it sound like that included removal/installation. Is that about right? That seems lika lot to throw into this old truck, but it isn't doing alot of good sitting and collecting snow at the moment, and can't imagine that it is worth much to sell with a bad transmission.

 

had same prob in my 97 replaced the exact solenoids as you but yes the 3-2 downshift will help but dont know how long it will work untill it needs to be replaced or rebuilt, and $2800 for a used seems really high i paid $250 for the three i got. and $1700 is about right to rebuild but try the soleniods first and try that