I will start by saying, the transmission was completely rebuilt with all new parts but I don't think the guy replaced the speed sensors on the side of the transmission if I'm correct.. I floored it one time and the trans went into Free Will mode. The engine went to the limiter and as soon as I let off the throttle the trans caught.. since then it has shifted like it had a shift kit in it.. I replaced the sensors to no avail.

Since then, once in a while, the speedometer will get erratic and or not move. Once that happens it will not shift out of first gear by itself. I can manually shift from first to second but that's it.. if I drive for a little while it finally goes away. This mostly happens in cold conditions but it has happened a few times in hot weather

Help!!

 

Never go to these rebuild guys. Always buy complete units from the big factories that supply everybody else, which have been dyno tested and come with a warranty. Now it'll have to come out again.

 

Never is a strong word. It's better to say, "ask around". I found an excellent AAMCO shop by asking several auto repair shops who they would recommend.
Don't rely on Yelp reviews. Went to a trans shop that had a 5 star yelp rating years ago. Turns out he knew nothing about GM electronic transmissions. After the third failure I took the car to my local Cadillac dealer. Got a factory rebuilt trans with a 3 yr / 36K warranty. Still running good 100,000 miles later.

 

Never is the correct word.
You just proved my point
That's what I'm saying.