GMC Repair: 1995 GMC Jimmy, transmission repair shop, gmc jimmy

Question
I have a 1995 GMC Jimmy SLS v6 4.3 2wd 149,000miles and my problem is this: after I changed my automatic transmission fuild and filter I drove it to work the next day while going home I had knoticed that the transmission wont shift into 3rd gear. then i replaced the 2 shifting sensors (which is the same part number)( 1 was bad ) I still get the same thing not shifting into 3rd gear. I tryed manual shifting and still is same thing. I get very little silver filings in the pan. I disconnected the possitive battery post to let the computer reset just incase it didnt reconize to shift. any help is appreciated thanks

Answer
Hi
I am not a heavy tranny tech, but I can tell you if it WAS NOT doing this before, it sounds like you MAY have dislodged a small piece of trash in the transmission and it has POSSIBLY lodged in the valve body, in the 2-3 shift valve bore.
The other items I can think of that would cause a no 3rd condition I do not see how changing filter and fluid could cause it.
Does it go into 4th then? OD? or does it just "race" through 3rd?
I would consider 2 things for you to attempt.
1) take it to a local shop that preforms transmission fluid flushes. This MAY help, but I really doubt it.
2) Take it to a reputable transmission repair shop in your area and talk to the service adviser or owner or whoever and explain IN DETAIL what you did and has been done. Let them then advise you on a repair option.
Ask friends/family/coworkers about a Transmission shop. If your regular repair shop does not do tranny work, ask them to refer you to one. If you know your mechanic well enough, see if he'll call the tranny shop and make appointment for you.
This is all just advise from experience.
I really hope it helps and
Good Luck
Paul