Help With Transmission!!

[2g2fast]

Hey guys i have a 1997 GST with a 6 bolt engine swap the transmission is acting up as an example
When the car is cold you can put the car in any gear and it will work after driving it for 15 minutes or so the only gear the car will go into is park. if you try to go into any other gear it wont do nothing it will just go to neutral.

Anyone else has had this issue share your story what you had to do to fix it? Or Help!!

 

[Firsts tuner]

I offered you a suggestion on your other thread about this issue. How does your fluid look? Have you put any additives in it ie Lucas, Trans Dr, anything like that. Are you getting any codes. Is it going into limp mode? Youll only have third in limp in so it'll feel like youre not going anywhere till the rpm's get up enough to move that higher gear. You said you just bought the car, have you done any basic maitenance to it? If not then youre setting yourself up for failure and youll give up. Check the trans fluid if it looks really new thats suspect, if not then change the filter and replace the fluid.