Hello, good to everyone! I have a problem after rebuilding my th350, the transmission had a completely manual transgo 350-3 kit mounted, well, after the reconstruction I do not have first gear, in the first gear position the second gear enters, when I put second gear There is no noticeable change, it simply continues in second gear, and third gear comes in as usual, as does reverse... I'm going crazy, any idea what the problem could be?

 

I don't know what kind of shifter linkage you are using. The only thing that would make sense is that something is not tight enough (or short/long enough ) to fully engage 1st. I've had a linkage be too short, and can push the gear selector too far or not enough, creating a neutral effect in first and then not able to go into reverse. I'm no expert by far but my very limited experience leads me to think this. I had a TH350 auto so my experience is not with a manual th350, with a different trans.

If the linkage pulls almost into first when it's supposed to be in neutral, it can jump into second, and having no higher gear, would only be able to go into third. I would guess that this problem in a 4 speed would cause 1st to be nonexistent like the 3 speed, but would probably jump 3rd from 2nd and go straight into 4th. Without seeing the linkages I cannot be sure, but to me this sounds like 1st isn't being engaged because something is not allowing the gear selector on the trans to move correctly. I think it's a shifter or linkage issue not a tranny issue. (The picture does not accurately represent how the linkage moves its just a rough idea.) Since you rebuilt a tranny you are obviously more experienced but I hope that I could at least provide something to consider. Good luck